Mary Anne Phagan (1899-1913) was born in Florence, Alabama, to William Joshua Phagan (1873-1899) and Frances Benton (1874-1947). She was the youngest of five children: Benjamin Franklin (1893-1971), Ollie Mae (1894-1963), Charlie Bryan (1896-1963), and William Joshua (1898-1973). In 1912, Frances Benton married John William Coleman (1858-1936) and the family moved to Atlanta, Georgia, where Mary Phagan worked at the National Pencil Company factory. On April 26, 1913, Mary Phagan was found murdered in the factory. Leo Frank, the factory manager, was convicted of the murder and sentenced to death. Georgia governor John Slaton commuted Frank's sentence to life imprisonment, which prompted a well-organized group to kidnap, beat, and lynch Frank. Frank's guilt remains highly contested.

Mary's brother William Joshua married Mary Delilah Richards (1901-1992) and had four children, James (1926-2004), Anne (1918-1996), Jack (1923-), and Betty (1931-2018). James Phagan named his daughter Mary Phagan (Kean) (1958-) after "Little Mary Phagan" and they worked to have her story remembered as well as against Leo Frank's post-mortem pardon. Frances Benton's brother, Durell Benton (1880-1941), also lived in Atlanta with his wife Lula (1881-1951) and his three children, Lex (1905-1973), Bertie (1906-1977), and Frank (1908-1964). Lex Benton married Anna Lee (1913-1997) and they had one daughter, Patricia (1930-2013).