Rumsey has a Bachelor of Arts and a Master of Fine Arts from Yale University and was a founding member of Yale Research Associates in the Arts also known as PULSA, a group of artists working with electronic technologies. He was also a 1966 initiate into the Skull and Bones Society, before becoming Associate Director of the American Society for Eastern Arts in San Francisco. Later, he entered a 20-year career in real estate development and finance during which he had a long association with Charles Feeney's General Atlantic Holding Company of New York and served as President and Director of several of its real estate subsidiaries; General Atlantic eventually became the Atlantic Philanthropies, a Bermuda-based philanthropic foundation that is one of the world's largest charities.
Rumsey was a lecturer in art at the Yale School of Art for several years. He has lectured widely regarding his online library work, including talks at the Library of Congress, New York Public Library, Digital Library Federation, Stanford University, Harvard University, Where 2.0, O'Reilly Open Source Convention, and at conferences in Hong Kong, Mexico, Japan, United Kingdom, and Germany.
Rumsey has collected from the early 1980s more than 150,000 rare 16th through 21st century maps of North America, South America, Europe, Asia, Africa, Pacific, Arctic, Antarctic, and the World. The collection includes separate maps, atlases, globes, school geographies, books of travel and exploration, and maritime charts. The collection is available on his website for free viewing.
The entire collection is now hosted in the David Rumsey Map Center that opened on April 19, 2016 in the Bing Wing of Green Library, Stanford University. The Center contains rare maps and atlases in addition to interactive, high-resolution screens for viewing digital cartography. The davidrumsey.com website continues as a separate public resource.
For making his map collection public through his (free) website, Rumsey was given an Honors award in 2002 by Special Libraries Association. The website, developed in conjunction with Luna Imaging and TechEmpower, won the Webby Award for Technical Achievement in 2002.
On May 18, 2012, Rumsey received the Warren R. Howell Award from the Stanford University Libraries in recognition of his service to Stanford.
As of January 2008, following are some of the institutions where Rumsey serves as a board member:
He is the author of the following books: