[1] Davis was born in Maryland in 1846 and grew up in the Colchester Township, Canada West area.

[2][3] He was the son of James Davis, a former slave from Virginia who came to Colchester Township, Canada West via the Underground Railroad in 1850.

[4] Delos started by teaching in school and then began to study law with Gordon Watts Leggatt and Charles Robert Horne of Windsor due to his dream of being a lawyer.

Since he was not able to find a law office that was willing to let him article with them, in 1884, William Douglas Balfour introduced a special act allowing Davis to practice as a solicitor if he passed the required Law Society of Upper Canada test.

From 1900 to 1905, he practiced with his son Frederick Homer Alphonso, who had graduated from Osgoode Hall.