Gilliam lived in Washington, D.C., with his long-time partner, Annie Gawlak. They were married in 2018 after a 35-year partnership. Career in the 1960s, early 1970s During the social upheaval of the 1960s in the United States, Gilliam began painting works that were abstract but still made bold, declarative statements, inspired by the specific conditions of the African-American experience. This was at a time that "abstract art was said by some to be irrelevant to black African life." Abstraction remained a critical issue for artists such as Gilliam. His early style developed from brooding figural abstractions into large paintings of flatly applied color, pushing Gilliam to eventually remove the easel by eliminating the stretcher. During this time period, Gilliam painted large color-stained canvases, which he draped and suspended from the walls and ceilings, comprising some of his best-known artwork. Gilliam was influenced by German Expressionists such as Emil Nolde, Paul Klee, and the American Bay Area Figurative School artist Nathan Oliveira. His early influences included Morris Louis and Kenneth Noland. He said that he found many clues about how to go about his work from Vladimir Tatlin, Frank Stella, Hans Hofmann, Georges Braque, Pablo Picasso, and Paul Cézanne. In 1963, Thomas Downing, an artist who identified himself with the Washington Color School, introduced Gilliam to this new school of thought. Around 1965, Gilliam became the first painter to introduce the idea of the unsupported canvas. He was inspired to do this by observing laundry hanging outside his Washington studio. His drape paintings were suspended from ceilings or arranged on walls or floors, representing a sculptural third dimension in painting. Gilliam said that his paintings are based on the fact that the framework of the painting is in real space. He was attracted to its power and the way it functioned. Gilliam's draped canvases change in each environment where they are arranged and frequently he embellished the works with metal, rocks, and wooden beams. He received countless public and private commissions for these draped canvases which earned him the title of the "father of the draped canvas". One of his last, and largest, works within this series was titled Seahorses (1975), made for the Philadelphia Museum of Art. The work consisted of six parts and was made of hundreds of feet of canvas hung on the outside walls of the museum. During the 1960s, Gilliam also experimented with beveled-edge paintings, often