William Lambert was born free sometime in 1817 in Trenton, New Jersey. Reports suggest that his father was a slave, while his mother was free at the time of his birth. Lambert worked and learned under Abner Hunt Francis, a Quaker schoolmaster, during his childhood. At the age of 13, he became a cabin boy on a Great Lakes vessel that sailed to Detroit. By 15, he was already a junior conductor of the Underground Railroad, aiding fugitive slaves in their journey to freedom.

​

By the age of 18, Lambert had settled permanently in Detroit, continuing his activities as an abolitionist. Alongside his efforts to assist runaway slaves, he worked as a tailor and eventually owned a tailoring and dry-cleaning business. His tailor shop stood on E. Jefferson, on the land now occupied by the Detroit Plaza.

​

By the time he turned 25, Lambert was recognized as a leader in Detroit's black community. In 1843, he organized the Convention of the Colored Citizens of Michigan and delivered the keynote address. In his speech, he advocated for equality for blacks, speaking out against racism and urging Michigan's white citizens to grant blacks the right to vote and political equality. Lambert argued that blacks deserved these rights based on the promises of the Founding Fathers, the support blacks had given in America's fight for freedom from the British, and simply because Africa was the cradle of human civilization. He stated,

​

"Therefore, we feel that our sufferings caused by our being deprived of our Political Rights should call forth the sympathies of the whole human race, but more especially those of yourselves, among whom we dwell and who are the authors of our calamities. For you have trampled our liberties in the dust, and thus standing with the iron heel of Oppression on our heads, you bid us rise to a level with yourselves; and because we do not rise, you point the finger of scorn and contempt at us, and say that we are an inferior race by nature."

​

For years, Lambert continued to assist the citizens of Detroit. However, he began to experience mental deterioration in 1890. On April 28, 1890, he tragically committed suicide by hanging himself.

​