Brown was born as Martha Frances Prattis in Federalsburg, Maryland, USA on 17 February 1858. Her parents, Alexander Prattis and Ellen Phillips, were freed slaves. In 1876, she moved to Philadelphia.
At some point, she married Luke H. Nichols, with whom she had seven children, including Rev. William Nichols (died 1966). Her first husband passed away in 1928. She worked as a seamstress and teacher. Her second husband, Benjamin Brown, passed away in 1932/1940/1942 (sources differ).
On her 111th birthday in 1959, she received a letter from President Richard Nixon, congratulating her on her longevity.
Brown passed away in Philadelphia, Pennsylvania, USA, on 5 August 1969, at the age of 111 years, 169 days. She was survived by her son, Louis (aged 71 at the time), and more than 40 grandchildren, great-grandchildren, and great-great-grandchildren.