Before the abolition of slavery, he was an abolitionist and worked with his close relative, George DeBaptiste in the Underground Railroad, mainly in Detroit, Michigan.

[3] There he continued his education under Richard Dillingham, a Quaker; and Reverend Samuel H. Davis, pastor of the Second Baptist Church of Detroit.

[2] In Detroit and later in Ohio and Chicago, DeBaptiste worked to help fugitive slaves escape to Canada.

He acted with George DeBaptiste (possibly his brother), a noted conductor of the Underground Railroad in Detroit.

[4] After moving to Chicago, DeBaptiste also worked with noted abolitionists John and Mary Jones.

DeBaptiste was ordained in April 1860 at Mount Pleasant, Ohio by a council called by the Union Baptist Church of Cincinnati.

[2] In addition to conducting his ministry, he taught public schools for black children in Springfield Township and Mount Pleasant for three years.

In August 1863, DeBaptiste was called to succeed Jesse Freeman Boulden as pastor of Olivet Baptist Church in Chicago.

He was elected president of the consolidated American Baptist Missionary convention in Nashville, Tennessee in 1867 and reelected for the following four years, including in 1870 at Wilmington, North Carolina, although he did not attend.

In 1870, he was elected president of the Baptist Free Mission Society, a white organization, at their meeting in Cincinnati.

Also in 1870, he was elected corresponding secretary of the American Baptist National Convention, which met August 25–29 in St.

At the 1877 meeting at Richmond, Virginia, DeBaptiste was elected corresponding secretary of the Foreign Mission department, a position he held for two years.

In 1881, he was elected corresponding secretary of the Baptist General Association of the Western States and Territories, and also held the position of treasurer of that group.

[10] He was also president of the Cook County Building and Loan Association of Chicago, an African-American group organized to promote black business.

Following the work of founder Ferdinand Lee Barnett,[11] he was co-editor with Reverend G. C. Booth at the Chicago Conservator.