One day in 1997, when Kristi Jacobson was working in the documentary division of ABC News, she glanced over a co-worker’s shoulder and noticed Toots Shor’s name in the New York Times crossword puzzle. Ms. Jacobson casually mentioned that Mr. Shor, the fabled New York saloonkeeper, was her grandfather. Her colleague, a history and sports buff, “freaked out,” Ms. Jacobson, 36, recalled recently.

“It was embarrassing, but I had to admit that I didn’t know much about my grandfather,” Ms. Jacobson said. When Shor died in 1977, Ms. Jacobson was all of 6 years old. There were a few pieces of memorabilia in her parents’ Rumson, N.J., home — autographed photos of Shor with President Dwight D. Eisenhower and other famous friends — but the family rarely discussed Shor, and Ms. Jacobson had little sense of his cultural significance.

That brief conversation with a colleague sparked a decade-long immersion in the life and lore of Shor, the Runyonesque character who turned the role of restaurateur into a celebrity archetype, became a symbol of the city’s midcentury apotheosis, and addressed everyone from bus drivers to movie stars with his signature epithet, “crumb bum.” The result is “Toots,” Ms. Jacobson’s feature-length documentary, which made its debut on Friday in New York to favorable reviews.