After the war, the senior Morris settled in York, married Barbara Myers and became a successful physician.

He demonstrated a strong aptitude for language and became fluent in German, Greek, Latin, French, and Hebrew.

For two years he studied with Samuel Simon Schmucker, an influential but controversial Lutheran religious leader.

Shortly after settling in Baltimore, Morris married Eliza Hay, member of a prominent New York family.

[5] When Morris joined the clergy, Lutheranism faced an internal struggle between liberals who sought to align with mainstream American Protestantism and conservative German immigrants who wished to maintain their traditions and language.

As pastor of First English for more than thirty years, Morris was a leading proponent of progressive, English-speaking Lutheranism in Baltimore.

In 1846 he toured Europe, meeting with European entomologists and viewing the insect collections at some of the major museums.

Unlike many of his colleagues in American entomology, he never accepted Darwinism and instead remained a supporter of Georges Cuvier's catastrophism.

[6] In 1851 Morris was elected to membership in the Maryland Historical Society, an organization that suited his scholarly interest in history.

One of his chief contributions to the Society was the effort he led to expand and improve both the library and the natural history collections.