The twentieth century was the period between January 1, 1901 and December 31, 2000.
- Richard Dressler: Most people believe the twentieth century was defined by the death struggle of capitalism versus communism, and that fascism was but a hiccup. Today we know better. Communism was a fool's errand, the followers of Marx gone from this Earth; but the followers of Hitler abound and thrive. Hitler, however, had one great disadvantage. He lived in a time when fascism, like a virus, like the AIDS virus, required a strong host in order to spread. Germany was that host, but strong as it was, Germany couldn't prevail. The world was too big. Fortunately, the world has changed. Global communication, cable TV, the internet. Today the world is smaller, and the virus no longer needs a strong host in order to spread. This virus is airborne... One more thing; let no man call us crazy. They called Hitler crazy, but Hitler wasn't crazy. He was stupid. You don't fight Russia and America. You get Russia and America to fight each other, and destroy each other.
- The last century was defined by physics. From the minds of the world’s leading physicists there flowed a river of ideas that would transport man kind to the very pinnacle of wonder and to the very depths of despair. This was a century that began with the certainties of absolute knowledge and ended with the knowledge of absolute uncertainty. It was a century in which physicists developed theories that would deny us the possibility that we can ever properly comprehend the nature of physical reality. It was also a century in which they built weapons with the capacity utterly to destroy this reality.
- Jim Baggott, The Quantum Story: A History In 40 Moments (2011), "Preface"
- The birth of the 20th century was like a flaming sunrise. More was expected of the century than any other. So much had been achieved in the previous one that it seemed sensible to expect that henceforth the world's triumphs would far outweigh the disasters.
- Geoffrey Blainey, A Short History of the Twentieth Century (2005)
- The political history of the 20th century is the history of social-engineering projects executed by well-intentioned people that began well and ended badly.
- [This century has been called] the century of extremes, . . . in which human vices reached unfathomable depths. [She notes that it has been] a century of great progress [and in some places of] unprecedented economic growth ... [At the same time, however, poor urban areas face a bleak future of] ... overcrowding and a disease pattern linked to poverty and an unhealthy environment.
- A child born tonight will have almost no memory of the 20th century. Everything that child will know about America will be because of what we do now to build a new century. We don't have a moment to waste. Tomorrow there will be just over 1,000 days until the year 2000. One thousand days to prepare our people. One thousand days to work together. One thousand days to build a bridge to a land of new promise. My fellow Americans, we have work to do. Let us seize those days and the century.
- Bill Clinton, 1997 State of the Union Address
- The speed of its collapse has exceeded all the other great landslides of European history, [and] it happened through natural causes ... the rise, development and collapse of the Soviet Union, ... [was] one of the most dramatic spectacles of the twentieth century.
- [The Soviet Union was] a vast multinational empire already sinking into irreversible decline.
- Third, we must develop our energy technology and resources so that the United States has the ability to supply a significant share of the energy needs of the free world by the end of this century. To attain these objectives, we need immediate action to cut imports. Unfortunately, in the short term there are only a limited number of actions which can increase domestic supply. I will press for all of them.
- Gerald R. Ford, 1974 State of the Union Address
- The peoples of Western Europe and North America seemed to have every reason to greet the twentieth century as the dawn of a new and happier age in the history of mankind.
- The First World War was a landmark in the history of East Asia and of the United States in many ways.
- As centuries go, this has been one of the most amazing: inspiring, at times horrifying, always fascinating.
- August 1, 1914: No one suspected that the 19th century, which had presented Europeans with a long period of peace, ended on that day; and no one noticed that the 20th century actually began only at that time—with a time of war lasting three decades and demonstrating what men can do to fellow humans.
- Cruelty and human brutality exceeded the worst expectations. In the trenches . . . seeds were sown for an era in which humans were viewed as material, not as individuals.
- The major political event of the twentieth century is the death of socialism.
- Irving Kristol, Neo-Conservatism: The Autobiography of an Idea (1995)
- For almost a quarter of a century the affairs of the world and its ideas have been in indescribable confusion. In most cases the confusion of ideas is manifest without the aid of polemic or controversy. It is simple evidence of the chaotic state of the world. The succession of events since 1914 has swept away so many illusions that even a summary inspection of the heap of ideological ruins would demand the compilation of a veritable encyclopaedia.
- At the outgoing of the old and the incoming of the new century you begin the last session of the Fifty-sixth Congress with evidences on every hand of individual and national prosperity and with proof of the growing strength and increasing power for good of Republican institutions. Your countrymen will join with you in felicitation that American liberty is more firmly established than ever before, and that love for it and the determination to preserve it are more universal than at any former period of our history
- William McKinley, 1900 State of the Union Address
- If we are to have peace in the last third of the century, a major factor will be the development of a new relationship between the United States and the Soviet Union. I would not underestimate our differences, but we are moving with precision and purpose from an era of confrontation to an era of negotiation. Our negotiations on strategic arms limitations and in other areas will have far greater chance for success if both sides enter them motivated by mutual self-interest rather than naive sentimentality. It is with this same spirit that we have resumed discussions with Communist China in our talks at Warsaw. Our concern in our relations with both these nations is to avoid a catastrophic collision and to build a solid basis for peaceful settlement of our differences. I would be the last to suggest that the road to peace is not difficult and dangerous, but I believe our new policies have contributed to the prospect that America may have the best chance since World War II to enjoy a generation of uninterrupted peace. And that chance will be enormously increased if we continue to have a relationship between Congress and the Executive in which, despite differences in detail, where the security of America and the peace of mankind are concerned, we act not as Republicans, not as Democrats, but as Americans.
- Richard Nixon, 1970 State of the Union Address
- As we look back over this century, let us, in the highest spirit of bipartisanship, recognize that we can be proud of our Nation's record in foreign affairs. America has given more generously of itself toward maintaining freedom, preserving peace, alleviating human suffering around the globe, than any nation has ever done in the history of man. We have fought four wars in this century, but our power has never been used to break the peace, only to keep it; never been used to destroy freedom, only to defend it. We now have within our reach the goal of insuring that the next generation can be the first generation in this century to be spared the scourges of war.
- Richard Nixon, 1972 State of the Union Address
- Revolution rather than reform was necessary ... but it took a major war, the First World War, and the consequent chaos, to precipitate the revolution proper.
- To many of us now, computers, silicon chips, data processing, cybernetics, and all the other innovations of the dawning high technology age are as mystifying as the workings of the combustion engine must have been when that first Model T rattled down Main Street, U.S.A. But as surely as America's pioneer spirit made us the industrial giant of the 20th century, the same pioneer spirit today is opening up on another vast front of opportunity, the frontier of high technology.
- Ronald Reagan, 1982 State of the Union Address
- Well, today physicists peering into the infinitely small realms of subatomic particles find reaffirmations of religious faith. Astronomers build a space telescope that can see to the edge of the universe and possibly back to the moment of creation. So, yes, this nation remains fully committed to America's space program. We're going forward with our shuttle flights. We're going forward to build our space station. And we are going forward with research on a new Orient Express that could, by the end of the next decade, take off from Dulles Airport, accelerate up to 25 times the speed of sound, attaining low Earth orbit or flying to Tokyo within 2 hours. And the same technology transforming our lives can solve the greatest problem of the 20th century. A security shield can one day render nuclear weapons obsolete and free mankind from the prison of nuclear terror. America met one historic challenge and went to the Moon. Now America must meet another: to make our strategic defense real for all the citizens of planet Earth.
- Ronald Reagan, 1986 State of the Union Address
- The earlier part of the twentieth century was defined by liberal democracy’s struggle against its rival ideologies of fascism on the right and communism on the left: to the point of hot and cold wars alike. Tocqueville’s “empire” of democracy, by which he meant its indisputable influence as an ideally, largely won those battles in the way that Western society was reassembled after the Second World War. The defining issue of our own era has therefore been something else entirely: more a full-throated struggle over democracy itself, a struggle to reconcile democratic equality with liberal freedom in an age of capitalist globalization. To tell the story properly we must discard the conventional narrative frame of the twentieth century: for its threads weave most meaningfully together not in 1945, nor even in 1989, but in the early 1970s, at the very point in which fascism and communism, as state forms, also finally began to yield their grip. It is there that the changes giving shape to the political order we have all been living through first set in. In the half-decade between 1968 and 1974 an entire era—the postwar era—came to an end and something else began: our present age. There was no single year of upheaval, though 1971, for reasons that will become clear, cusps this change. There was no singular break, either, between some uniformly experienced before and after. But amid a perfect storm of crises that befell both East and West alike, the very structure of democracy that had sustained the Western nations through the first half of the twentieth century appeared suddenly to have run its course. That wider constellation of crises included the most dramatic transformation of the world economy since the Great Depression, and a fracturing of territorial sovereignty which, for the best part of two centuries, had underpinned national and international politics alike. It included the upheaval of rapidly modernizing societies at home, whose citizens suddenly demanded of their governments what their governments could not provide. The response to those crises in the East, we know well, was more repression at home and more credit from abroad to shore up their failing regimes: a path that ultimately led to the collapse of the entire communist system. But what of the response tin the West. As historians are beginning to document, something more radical happened: the West underwent “regime change.” From around 1971, on the back of the social upheavals of the late 1960s, with the Nixon administration in America at its most reckless and radical groups rising across Europe; with people marching on the streets and a crisis in the international economy, the postwar consensus unraveled and the institutional arrangements of the liberal democratic order began to be reconfigured.
- Simon Reid-Henry, Empire of Democracy: The Remaking of the West Since the Cold War, 1971-2017 (2019), pp. 4-5
- [T]he history of the 20th century was basically that of the swath of destruction left across the globe by socialist ideas, from the international socialism of the Bolsheviks and the Soviet Union to the national socialism of Adolf Hitler and his National Socialist German Workers' Party.
- Any history of the twentieth century must begin in a world deeply unlike our own. At least in the most 'western', developed societies, we are less like the men and women of 1901, and further distanced in our thinking and behaviour from them than, say, were they from their forebears of a century earlier.
- J. M. Roberts, The Penguin History Of The Twentieth Century (2000)
- The tremendous and highly complex industrial development which went on with ever accelerated rapidity during the latter half of the nineteenth century brings us face to face, at the beginning of the twentieth, with very serious social problems. The old laws, and the old customs which had almost the binding force of law, were once quite sufficient to regulate the accumulation and distribution of wealth. Since the industrial changes which have so enormously increased the productive power of mankind, they are no longer sufficient.
- Theodore Roosevelt, 1901 State of the Union Address
- The Congress has wisely provided that we shall build at once an isthmian canal, if possible at Panama. The Attorney-General reports that we can undoubtedly acquire good title from the French Panama Canal Company. Negotiations are now pending with Colombia to secure her assent to our building the canal. This canal will be one of the greatest engineering feats of the twentieth century; a greater engineering feat than has yet been accomplished during the history of mankind. The work should be carried out as a continuing policy without regard to change of Administration; and it should be begun under circumstances which will make it a matter of pride for all Administrations to continue the policy.
- Theodore Roosevelt, 1907 State of the Union Address
- The line separating good and evil passes not through states, nor between classes, nor between political parties either – but right through every human heart…even within hearts overwhelmed by evil, one small bridgehead of good is retained. And even in the best of all hearts, there remains…an uprooted small corner of evil.
Thanks to ideology the twentieth century was fated to experience evildoing calculated on a scale in the millions.
Alas, all the evil of the twentieth century is possible everywhere on earth. Yet, I have not given up all hope that human beings and nations may be able, in spite of all, to learn from the experience of other people without having to go through it personally.
- Anyone desiring a quiet life has done badly to be born in the twentieth century.
- In Asia and Africa, the economic and social problems are different but no less urgent. There hundreds of millions of people are in ferment, exploding into the twentieth century, thrusting toward equality and independence and improvement in the hard conditions of their lives.
- Harry S. Truman, 1953 State of the Union Address
- Encyclopedic article on 20th century on Wikipedia