The yellow taxi pulled up to a sidewalk in downtown Milwaukee. It was Friday afternoon, the weekend before Thanksgiving, and traffic was brisk.

A 27-year-old man hopped inside. As he sped off, the cabbie asked, “Have you heard about Kennedy?” Thinking it was the start of a new joke, the young man eagerly leaned forward and grinned. “No, I haven’t. How does it go?”

What followed wasn’t funny. The president had been assassinated in Dallas. And while it was a tragedy for the nation, it was a personal blow to that young man in Milwaukee. When Nov. 22 dawned, the cabbie’s passenger was famous. He went to bed that night a has-been.

Vaughn Meader was born in 1936 to a working-class family in Maine. While still a toddler, his father broke his neck and drowned in a diving accident. His widowed mother took a job as a cocktail waitress in Boston, leaving the child with relatives. Perhaps not surprisingly, Meader was a troubled kid. Unruly at times, he was shuttled between his mother (who was sinking into alcoholism) and various children’s homes.

He also enjoyed the limelight. He did a stint in the Army after high school. Stationed in West Germany in the late 1950s, he formed a G.I. country music group, with him also doing impressions of famous singers.

Meader married a German woman, returned stateside, and plowed into the entertainment field in New York. His comedy act featured a spot-on imitation of President Kennedy, who was just taking the national stage. Handsome and with similar features, he copied Kennedy’s mannerisms and even resembled him a little. Audiences loved it. When JFK moved into the White House, Meader found his calling.

He made history on Oct. 22, 1962, when he and a small cast recorded “The First Family.” The album charted new territory by gently parodying the Kennedy family. There had never been anything like it before. (“Saturday Night Live” was still 13 years away.) The recording was an overnight smash hit, selling 1.2 million copies in just the first two weeks. Sales eventually totaled 7.5 million LPs, a record — until the Beatles came along and obliterated it.

Kennedy, incidentally, relished the attention the hit record unexpectedly brought him. Asked at a presidential news conference if he’d heard it, JFK said he had, adding, “I thought it sounded more like Teddy than me.” He gave the album to close friends that Christmas and even quipped at a Democratic Party gathering, “Vaughn Meader was busy tonight, so I came myself.”

Overnight, Vaughn found himself “the second most famous man in the country,” according to one newspaper. He was the toast of the entertainment world, appearing on the era’s biggest TV shows (Ed Sullivan, Jack Paar, Andy Williams, “To Tell the Truth” and “What’s My Line?” among them). Frank Sinatra even invited him to join the Rat Pack. These were the glory days for Meader.

Then Kennedy went to Dallas.

Iconoclastic comic Lenny Bruce didn’t let the assassination keep him off stage on the night of Nov. 22. He walked up to the mic, was silent for a long stretch, then finally said, “Boy, Vaughn Meader is totally screwed.”

Bruce was right. All TV appearances and concerts were canceled. Though Meader was already working on a second non-Kennedy album, it was instantly shelved. In the profound national grief following the murder, Americans didn’t want to hear from a comedian who reminded them of their lost leader.

That’s when Meader’s life hit the skids.

The new album — “Have Some Nuts!!” — bombed when it came out in 1964. Depression set in. His drinking was out of control. His wife left him. He slept around and turned to drugs (which grew progressively harder). The few times he could land gigs, fellow comedians described him as “insufferable.”

There were three more marriages. He lost himself in religion. He made another album, this one called “The Second Coming,” about Jesus Christ returning to earth in the days of “Jesus Christ Superstar.” Sales were again in the cellar.

By the 1970s, he was living in his final wife’s hometown of Louisville, Ky., playing piano and singing as Abbott Meader (his first name), hustling any honky tonk date he could rustle up. He also dabbled in bluegrass music back in his native Maine. But it was nickel-and-dime stuff, and he existed on the financial edge.

Meader made a few late-life cameo performances (including the 1976 film “Linda Lovelace for President”) and even had a tiny spot on the 1981 comedy album lampooning Ronald Reagan called “The First Family Rides Again,” featuring Rich Little. It was a modest success … but nothing spectacular like the original.

By the end, Meader was barely able to breathe as he battled chronic obstructive pulmonary disease. He was toothless, bearded and still angling for a comeback right up until he died at age 68 in 2004.

Despite being little more than the answer to trivia questions today, he had been a pioneer. He paved the way for Little, “SNL,” and a wide range of presidential impressionists

They all owe their success to Vaughn Meader, the comedy trailblazer who lost it all in an instant one November afternoon.