He helped to found the Republican Party in New York and was a strong supporter of the Presidency of Abraham Lincoln.

In 1836 he moved to New York City, becoming a successful wholesale grocer and bond broker.

Appointed a major general of volunteers in the Union Army, he commanded the military's Department of New York while serving as governor.

[1] The family moved to Windsor, Connecticut, where Morgan received his early education before attending Bacon Academy in Colchester.

Solon Humphreys was taken in as a full partner in 1854 after working several years as an agent in St. Louis, Missouri.

Nearly two-thirds of the bonds issued by the State of Missouri from 1835 to 1860, plus a large share of securities of St. Louis, were sold through the house of Morgan – in all perhaps thirty million dollars worth.

[2] In 1849, Morgan was elected as a member of the New York City Board of Assistant Aldermen.

In January 1869, he sought re-nomination, but was voted down by the Republican caucus of State legislators who instead nominated Ex-Governor Reuben E. Fenton.

In 1881, Morgan was nominated by President Chester A. Arthur as Treasury Secretary and was confirmed by the Senate, but declined the position.