Modern political history offers no more astonishing story than the account of how the American conservative movement emerged, seemingly out of nowhere, in the early 1950s, trounced the regnant liberals, and established itself as the dominant political force in the United States. Professional historians have been slow to take up the task, no doubt because so many of them are liberals themselves and find the story positively painful to recount.

But in recent years the bookshelves have begun filling with accounts written by people who were themselves participants in the movement. And one that has just been published deserves the attention not only of conservatives eager to learn the origins and history of their cause, but of liberals genuinely interested to know how it all came about. The book is “Upstream: The Ascendance of American Conservatism” by Alfred S. Regnery (Threshold Editions), and it can be recommended unreservedly.

Regnery is the son of the late Henry Regnery, who made a career of publishing conservative books that would otherwise never have seen the light of day, and is himself the publisher of The American Spectator, a well-regarded journal of conservative opinion. He gives us a clear chronological account of the birth and growth of the conservative movement, and then supplements this with extensive descriptions of the interface between the movement and such important aspects of our culture as the law, the economy and religion, among others.

It was in the early 1950s that Lionel Trilling made his famous observation that “In the United States at this time liberalism is not only the dominant but even the sole intellectual tradition. For it is the plain fact that there are no conservative or reactionary ideas in general circulation.” The observation was accurate, but on the ragged edge of obsolescence. In the mid-1950s, the late William F. Buckley Jr. assembled a varied group of conservative intellectuals under the banner of his magazine National Review and launched a full-scale counterattack on the liberals — denouncing their appetite for Big Government, calling for a return to the values of the Western Christian tradition, and demanding staunch resistance to world communism. Later in the decade, Russell Kirk launched his quarterly, Modern Age, on much the same principles, and by 1960 a whole new intellectual movement was under way.

It quickly moved into politics, and in 1964 captured the Republican Party, nominating Barry Goldwater for president. Goldwater’s subsequent defeat, far from dispiriting the movement, actually energized it. Within two years Ronald Reagan, its new spokesman, won the governorship of California by a million votes, and in 1980 and 1984 he was elected and re-elected president of the United States. In 1991 the Cold War ended in victory for the West.

This is the story that Regnery tells, but he goes well beyond its basic outlines. He highlights differences of opinion within the movement, and devotes whole chapters to important aspects of policy. One entire chapter concentrates simply on Reagan — as an anti-Communist, a movement conservative, a governor, a teacher, a politician, a president, a Cold Warrior, a supply-sider, and a revolutionary.

It is, I repeat, an astonishing story. Where are the liberals today? When did they last have a truly creative idea? Why is the very word so often avoided today, in favor of some substitute such as “progressive”?

In titling his book “Upstream,” Regnery makes the point that the success of the American conservative movement has been a battle every step of the way. There have been no easy victories. The dominant liberals of 1950 did not — as Trilling’s observation makes clear — even regard them as a threat. That was their first, and biggest, mistake.

(William Rusher is an accomplished author, former publisher of the National Review and former vice chairman of the American Conservative Union.)