[6] Her niece was Sadie Tanner Mossell Alexander, the first black woman in the United States to earn a Ph.D[7] and the first president of Delta Sigma Theta.

[4] After her husband's death, Johnson, then Halle Dillon returned home to her family and entered the Women's Medical College of Pennsylvania at the age of 24,[3] graduating with honors in 1891.

[5] In Alabama, Johnson was tutored by Dr. Cornelius N. Dorsette at Hale Infirmary to prepare for the medical exam.

[11] This rigorous exam required participants to give written responses to verbal questions from the state health office.

[11] Johnson was under heavy scrutiny and the public eye due to her race and gender, but successfully passed the examination to become the first woman physician in Alabama.

[3] In 1900, the Johnsons moved to Nashville, Tennessee, where John became a minister at Saint Paul's AME Church.