It was the summer of 1976. In New York City, the infamous serial killer David Berkowitz, known as the “Son of Sam,” launched his yearlong terror spree. At the Olympic Games in Montreal, Romanian Nadia Comaneci wowed audiences by posting the first ever perfect “10” for a gymnastic routine. On the airwaves, British rocker Peter Frampton’s groovy “Baby I Love Your Way” was rocking the country. And at the Republican National Convention in Kansas City that August, the president of the United States, Gerald Ford, was in a neck-and-neck battle for his party’s nomination with an upstart former California governor: Ronald Reagan.

Though Ford would narrowly edge out Reagan in the delegate count — 1,187 to 1,070 — the Golden State conservative’s upstart campaign triggered something far more profound: the reinvigoration and reorientation of a Republican Party, which had been soundly beaten in the midterm elections just two years before and was widely viewed as on the verge of extinction.

How Reagan, a former B-movie actor, accomplished such a feat is chronicled in painstaking detail in “Reagan’s Revolution: The Untold Story of the Campaign That Started It All,” a new book by longtime political activist and consultant Craig Shirley, which offers an intense, blow-by-blow insider’s account of Reagan’s failed primary challenge to Ford.

While most aspects of the 40th president’s career and life have been thoroughly plumbed, Shirley said the 1976 campaign remained the one chapter in the Reagan saga that had yet to be examined from a historical perspective.

“George Bush got here because of what Ronald Reagan did then. The Republican Party got here because of what Ronald Reagan did then,” asserted Shirley, as he held forth from behind his cluttered desk (which has a direct view on a large framed photo of Ronald Reagan circa 1980s) on a recent Thursday morning.

“If he didn’t run in 1976 he wouldn’t have run in 1980,” Shirley continued. “If he doesn’t run in 1980 then there is no Reagan revolution and with that there may have been no destruction of the Soviet Union, no victory over communism, or the fall of the Berlin Wall or the reordering of the two major political parties where one becomes suspicious of government and the other becomes addicted to government — you might not have had the clear choice that the American people have now.”

In opposition to the more moderate wing of the Republican Party, which dominated the GOP at the time, Reagan advocated in favor of federalism, a tougher foreign policy stance vis-à-vis the Soviet Union and lower taxes, Shirley said. That message, he added, held considerable appeal to many Americans unnerved by the series of social upheavals and foreign policy defeats — from Vietnam to Watergate — which had shaken the nation beginning in the early 1960s with the assassination of then-President John F. Kennedy.

The largely forgotten 1976 GOP primary campaign held a natural fascination for Shirley, who became a Reaganite in elementary school after hearing a recording of the pro-Barry Goldwater speech Reagan delivered during the 1964 Republican National Convention. In 1976, the year of Reagan’s second bid for the presidency (he briefly floated his name as an alternative to Richard Nixon at the 1968 Republican convention), Shirley was still in college; and though he had been a Reagan supporter, he dutifully performed the role of “grunt” in support of Ford’s general election bid that fall.

Ford lost that election to Jimmy Carter, which provided an opening for Reagan’s very distinct brand of conservativism to take flight. “The candidates who ran in ’78 … all ran as children of Reagan,” said Shirley, who first met Reagan when he was working on Gordon Humphrey’s (R-N.H.) successful Senate bid that year, and Reagan came to the old New Hampshire Highway Hotel near Concord to cut a 30-second TV commercial for Shirley’s candidate.

“He was utterly, utterly charming,” recalled Shirley, who would go on to serve a stint on Capitol Hill as a Humphrey aide. “On the first take he just did it flawlessly.”

Shirley would get to know Reagan better during his subsequent work on two independent campaigns in support of Reagan’s successful 1980 and 1984 presidential bids. His enduring admiration for Reagan is evidenced in his personal life. Shirley named his youngest son Mitchell Boman Reagan after the late president. And when he and his wife, Zorine, purchased a second home on the Rappahannock River in Lancaster, Va., they appropriately christened it “Trickle Down Point” in honor of Reaganomics.

Shirley, who by day is the president of the conservative Shirley & Banister Public Affairs — his publisher, Nelson Current, is also a client — spent much of the past 18 months writing the tome, but still found time to co-found the Republican-leaning 527 group Americans for a Better Country. (The group was formed mainly as a means of forcing the FEC to clarify the law on the election-related activities of 527 groups, he said.) Shirley skipped the GOP convention in New York last year to work on the book, and even converted a small room in his firm’s building into his writing office — partly papering the walls with chapter outlines.

As part of his research, Shirley interviewed more than 100 players — from former aides to journalists — active during the Ford and Reagan campaigns (including an hour and a half sit-down with Vice President Cheney, chief of staff during the Ford administration, that appropriately took place the morning of Reagan’s memorial service in the Capitol Rotunda last June). He will donate the tapes of these interviews to the Ronald Reagan Presidential Library in Simi Valley, Calif.

The book may also make it to the small screen. Earlier this week, the Virginia-based production company Light Year Multimedia Studios debuted a trailer for a documentary based on the book at a television trade show in Las Vegas.

Looking ahead, the first-time author is already considering writing additional books, including two more on Reagan: one, which may focus on his successful 1980 bid for the presidency, and a second on Reagan’s tenure as head of the Screenwriters Guild. Beyond political history, Shirley says he would also like to tackle a biography of legendary tap dancer Bill Robinson, the so-called Mr. Bojangles.

As for the 1976 campaign, Shirley ends the book on an ambiguous note, posing a series of theoreticals in the epilogue that could have potentially swung the race one way or the other, possibly avoiding the drawn-out fight to the finish that occurred.

Though Shirley doesn’t claim to have a definitive answer to the questions he puts forward, he does suggest that a higher power may have had a hand in Reagan’s trajectory.

“Maybe America needed to see for some reason what a disaster Jimmy Carter was in order to see what a brilliant success Ronald Reagan could be,” Shirley posited. “Maybe that was what was providential.”