Fred Bass, who transformed his father’s small used-book store, the Strand, into a mammoth Manhattan emporium with the slogan “18 Miles of Books,” died on Wednesday at his home in Manhattan. He was 89.

The cause was congestive heart failure, said Leigh Altshuler, the Strand’s director of communications.

Mr. Bass was 13 when he began working at the Strand, founded by his father, Benjamin. At the time, it was one of nearly 50 such stores along Fourth Avenue.

Except for two years in the Army, he never left, until retiring in November 2017.

A year after taking over as manager of the store in 1956, he moved it from Fourth Avenue to its present location, on Broadway at 12th Street, where it occupied half the ground floor of what had been a clothing business. He set the Strand on a path of unstoppable expansion, taking over the entire first floor, then, in the 1970s, the top three floors, and adding an antiquarian department.