He was among the founders of the Bethel Literary and Historical Society and the American Negro Academy, both based in the capital.

He also was a founder, editor, or contributor to a number of newspapers and journals, including most prominently The People's Advocate.

In the latter half of his career, he wrote articles and manuscripts and gave speeches, establishing himself as a leading scholar of African-American history.

He moved to a teaching school, the Preparatory Department of the Institute for Colored Youth, where Ebenezer Bassett was the principal.

By the end of 1865 Cromwell returned to Philadelphia; he taught at the Baltimore Association for the Moral and Intellectual Improvement of the Colored People.

That year, Cromwell was an eyewitness to the assassination of Joseph R. Holmes, a fellow member of the Constitutional Convention and a candidate for the Virginia House of Delegates.

In the meantime, in 1872, Cromwell passed the civil service exam to qualify for an appointment in the federal government.

In 1873 and 1874, Cromwell was twice promoted in his clerkship and, along with Robert William Waring, was one of the first two black clerks to receive such an office.

[1] In 1875, Cromwell was a part of organizing the Virginia Educational and Historical Association; he served as its president until 1883, when it closed.

[1] In 1881 Cromwell and Daniel Alexander Payne founded the Bethel Literary and Historical Association, and he served as president of that lyceum in 1883.

[4] Beyond his work as an educator, Cromwell played a significant role in the direction of black American thought.

The Bethel Literary Organization, which he helped create and direct, and his speeches at other lyceums in the capital were highly influential.

He had great contempt for efforts to minimize the cost of slavery to blacks in America and focused significant attention on slave insurrections.

Cromwell wrote that Nat Turner's revolt was an example of black people working to "help himself rather than depend on the other human agencies for the protection which could come through his own strong arm.

The couple stressed the importance of education for all their children, who included Otelia, Mary E., Martha, Lucy, John Wesley Jr., and Brent.

John Wesley Cromwell Jr. was born in 1883 and taught mathematics, German, and bookkeeping; he became the first black certified public accountant.