That year he also starred in the Andy Warhol film of the same name, which featured Mr. Indiana very slowly and languorously eating a mushroom. Then came “love.”
Although few fans seem familiar with the background, the art historian Susan Elizabeth Ryan revealed in her monograph on Mr. Indiana that the first version of his most famous work was markedly different. Completed “within complex circumstances” at the end of 1964, after Mr. Indiana and Mr. Kelly had broken up, Ms. Ryan wrote, it had a cruder four-letter word in place of “love,” in a similar composition with a tilted “u.”
Mr. Indiana never fully discussed, at least not in public, why he made the transition to the G-rated version, which he used as his Christmas card that year. The next year, he turned it into a Christmas card for the Museum of Modern Art in New York. By 1966 he had done enough variations on the theme to have a show of “Love” prints, paintings and sculptures at Stable Gallery in New York.
By 1970, when he built a 12-foot-tall steel version for the Indianapolis Museum of Art, the image was famous enough to be invoked — some would say stolen — by the book jacket design for Erich Segal’s best-selling novel “Love Story.” (This was long before Mr. Indiana’s dealers started chasing after any copyright infringements.)
Mr. Indiana believed the piracy of the image harmed his reputation in the New York art world, and he retreated to Maine in 1978. But many critics countered that he had appropriated his own work shamelessly for decades. He created dozens of versions of “Love” in different mediums, planted “Love” sculptures in cities from Indianapolis to Tokyo, and cast it into different languages, including Hebrew (“Ahava”) and Spanish (“Amor”).
He also revamped the slogan for political ends. In 1976, he recast “Love” as “Vote” for a poster commissioned by the Democratic National Committee. In 2008, he built a sculpture for the Democratic National Convention using the word “Hope” and authorized the image’s reproduction on T-shirts, buttons and limited-edition prints sold by Barack Obama’s presidential campaign.
Mr. Anderson, the former Indianapolis and Dallas museum director, said that “Love,” too, should be remembered in a broader political context, as a product of the 1960s. “To be true to the artist’s intentions,” he said, “we should see ‘Love’ in relation to the antiwar moment, and not as a decal on a baby boomer’s Volvo.”