The annual hoopla for Presidents’ Day car sales will soon be in full swing. But when did the holiday become synonymous with auto-selling extravaganzas?The idea, according to many, was the brainchild of Alvan T. Fuller, who was born in Charlestown and grew up in Malden. Fuller is perhaps best remembered for his tenure as Massachusetts’ 52d governor, when he refused to pardon anarchists Nicola Sacco and Bartolomeo Vanzetti before they were put to death for murder in 1927. But long before his career in politics, Fuller was just an enterprising teenager selling bicycles out of a backyard barn on Cross Street in Malden.As early as 1897, he was hyping Washington’s Birthday as a great time to buy bikes, hanging a sign outside his shop that read, “COME ON IN . . . IT’S OPEN HOUSE,’’ according to a Boston Globe story printed in 1964. When he transitioned to selling cars a few years later, Fuller again used Washington’s Birthday (the holiday wasn’t called Presidents’ Day until 1971) as a sales hook.“He said to himself, ‘Geez, if it worked in the bicycle business it’s got to work in the car business,’ ’’ said Fuller’s grandson, Peter Fuller Jr., who followed both his grandfather and father, Peter, into auto sales.Alvan Fuller’s 1958 obituary in the Globe gives him sole credit for having “inaugurated the Washington’s Birthday display of new autos.’’ Contemporary news stories often echo that sentiment, but delve deeper into history and such claims appear a bit embellished. While it’s true that Fuller held bicycle sales on Washington’s Birthday in the late 1890s, so did other bike shops around that time, wrote Globe reporter James T. Sullivan in a 1916 article. Like Fuller, some of those bike shop owners also became car salesmen at the turn of the 20th century and hosted open houses on the holiday.But even if Fuller didn’t begin Presidents’ Day sales, he alone popularized the idea, Sullivan wrote. Fuller’s elaborate holiday sales were leagues above his competitors’: they included live orchestras, decorations, and personal invitations to peruse his Boston showrooms. He stayed open later than any other dealership in the city and offered innovative deals that other car sellers couldn’t imagine.“He did a lot of things that were ahead of his time,’’ said Peter Fuller Jr., who runs a small car rental agency and used car dealership in Watertown. “He allowed customers to make payments for cars instead of asking them for all the money up front. Obviously, that’s the way everyone finances cars today, but he was one of the first to do that.’’Risk-taking was indeed Alvan Fuller’s forte. In 1899, he traveled to France to buy a pair of cars, becoming the first to import foreign models to Boston, according to Globe archives.