"[2]: 178  When Gardner submitted Reasonable Doubt to William Morrow, an editor suggested that "Della Street is a better character than the secretary."

Gardner took this suggestion when he rewrote Reasonable Doubt as The Case of the Velvet Claws and made Della Street Perry Mason's secretary.

Several instances of sexual tension are seen between Mason and Street in the Gardner novels, multiple glances, kisses, and so on, and several proposals of marriage, all of which Della turned down because, at the time, wives of professional men did not work.

Erle Stanley Gardner, the creator of Perry Mason in a series of novels, was a very prolific author, who simultaneously employed three secretaries—all sisters—to keep up with his output.

She was succeeded in the role by Joan Alexander, better known for portraying Lois Lane in the Superman radio series, and Jan Miner (Palmolive's "Madge").

On television, Della Street was played by Barbara Hale in the series, for which she received an Emmy Award, and in the 30 made-for-TV movies.