It’s no secret that people are often erased from the history of big-tech companies. It’s so prevalent in Silicon Valley that it is known as “The Creation Myth.” But what may come as a surprise is the number of women who played a pivotal role but who are now forgotten.

That is one of the central themes in Mr. Isaacson’s new book, “The Innovators: How a Group of Hackers, Geniuses, and Geeks Created the Digital Revolution,” due out Tuesday. Unlike his previous four books, all biographies of individuals, his new work is about groups and how the greatest innovations were all shaped by them.

In many respects, the book could have been called “The Collaborators.” Each chapter reinforces the core premise that Mr. Isaacson made after 15 years of research: That every technology innovation, whether programming code, transistors, personal computers or the Internet, was built by groups of people (usually by borrowing from past ideas).

But while a number of the men have become celebrities, most of the women are lost in a distant fog.

Ms. Lovelace’s role in tech, for example, is so paramount that her story is the opening and closing chapter. An English mathematician and writer, she wrote the first-ever computer algorithm, put forth the idea that humanities and technology should coexist and dreamed up the concept of artificial intelligence.

“Ada Lovelace defined the digital age,” Mr. Isaacson said in one of several recent interviews about the book. He was sitting outside the Blue Bottle coffee shop in Mint Plaza in San Francisco, known as a hothouse for programmers and venture capitalists. “Yet she, along with all these other women, was ignored or forgotten.”