Davis was born in Washington DC in 1920, and spent nearly all his life there. Before he began to paint in 1949, he worked as a sportswriter, covering the Washington Redskins and other local teams. In the late 1940s, he covered the Roosevelt and Truman administrations, and was often President Truman's partner for poker games. His first studio was in his apartment on Scott Circle, and later he worked out of a studio on Pennsylvania Avenue. His first solo exhibition of drawings was at the Dupont Theater Gallery in 1952, and his first of paintings was at Catholic University in 1953.

Though he worked in a variety of media and styles, including ink, oil, acrylic, video, and collage, Davis is best known by far for his acrylic paintings (mostly on canvas) of colorful vertical stripes, which he began to paint in 1958. The paintings typically repeat particular colors to create a sense of rhythm and repetition with variations. One of the best well-known of his paintings, "Black Grey Beat" (1964), owned by the Smithsonian American Art Museum reinforces these musical comparisons in its title. In 1972 Davis created Franklin's Footpath, which was at the time the world's largest artwork, by painting colorful stripes on the street in front of the Philadelphia Museum of Art, and the world's largest painting,Niagara (43,680 square feet), in a parking lot in Lewiston, NY. His "micro-paintings", at the other extreme, were as small as 3/8 of an inch square.

Davis began teaching in 1966 at the Corcoran School of Art, where he became a permanent member of the faculty. His works are in the collections of, among others, the Corcoran Gallery of Art, the Solomon R. Guggenheim Museum, The Phillips Collection in Washington, DC, Walker Art Center in Minneapolis, MN, and the Smithsonian American Art Museum.

He died of a heart attack on April 6, 1985.