Mary Cree Cosby moved to Bowie with her husband in 1909. In 1935, at the age of 56, she created her first baptistery painting. The painting was for the First Baptist Church of Bowie. The news of her special talent spread by word of mouth, and she was soon commissioned to do baptistery paintings in several churches throughout Montague County.
Cosby also painted the one located in the Buckner Orphans Home in Dallas, Texas. Her work, which can be found in churches in Kentucky, Mississippi, North Carolina and Texas, became so well-known that people traveled to Bowie to watch her at work in her studio.
She completed 411 such works during her career, and the vast majority of her paintings depicted the Jordan River flowing directly into the baptistery.