[1] He was the eldest son of John Garrison Murphy and Clarissa Runyon, a New Jersey couple who settled in Brooklyn after their marriage.

[2] John Murphy was a prominent businessman, and his accomplishments included inventing and patenting in partnership with another individual a horse-powered wheel for use on East River ferries, which enabled them to change direction for round trips without having to turn around.

[5] Henry Murphy graduated from Columbia College in 1830, studied law under Judge Peter W. Radcliffe, was admitted to the bar, and practiced in Brooklyn.

When the convention deadlocked after several ballots on the selection of a presidential nominee, the delegation from Virginia decided to support a dark horse—a northerner whose views on slavery were acceptable to southerners (doughface)—who they intended to vote for as a unit in the hopes of rallying enough delegates around one candidate that he could win the nomination.

[20] Murphy cast his ballot for George F. Comstock in the caucus held to choose the Democratic nominee, and again in the full legislative election.

[23] Murphy was the choice of Democrats in the legislature for the United States Senate in 1869, but the Republican majority elected Reuben Fenton.

[28] When the project was converted to a public work, Murphy was elected president of the New York and Brooklyn Bridge Company Board of Trustees, the entity created to plan, oversee construction of, and operate it.

[30] During his residence at The Hague as American Minister he printed for private distribution two monographs, Henry Hudson in Holland: Origin and Objects of the Voyage which Led to the Discovery of the Hudson River (1859) and Jacob Steendam, Noch Vaster: A Memoir of the First Poet in New Netherlands, with his Poems, Descriptive of the Colony (1861).

The latter of these was reprinted in his Anthology of New Netherland: or, Translations from the Early Dutch Poets of New York, with Memoirs of their Lives, issued by the Bradford Club in 1875.