Many of the letters written by C. A. L. Lamar about his illegal transatlantic slave trade enterprise of the late 1850s were addressed to Trowbridge ("Trow") in New Orleans.

Lamar and Trowbridge, who had had several businesses together, from breeding racehorses to mining for gold, were responsible for at least one blockade-runner, the Ceres, during the American Civil War.

"[2] In what might well have been a case of wartime sour grapes or might have been a statement of facts, in 1864, a Burlington, Vermont newspaper printed the following assessment of Trowbridge's character based on local recollections of his youth in Vermont:[3] N. C. Trowbridge, who figures so prominently in the Lamar correspondence, is Nelson Clement Trowbridge, a native of Cambridge, Vermont, who after being guilty of many mean tricks, fled from his birth-place many years since to tbe South, where he married a fair Southron with "lots of nigs."

[3]In 1846, newspaper reports show that Trowbridge was engaged in breeding and betting on horses with Charles Augustus Lamar of Georgia.

[7] Letters written by Trowbridge were amongst the cache looted from the office of Richmond slave trader R. H. Dickinson by Lucy and Sarah Chase.

From these letters, scholars of American slavery have evidence that traders would sometimes let potential buyers "test out" slaves on a trial basis.

Slave traders would also do "swaps," with Trowbridge writing Dickinson, "I exchanged your boy Patrick today and got a No.

[14] At the time of the 1850 U.S. census Trowbridge lived in Richmond County, Georgia, and reported that his occupation as "speculator.

[16] In 1856, Trowbridge, Lamar and others were investors in the Park Mine in Columbus County, Georgia that yielded at least two gold nuggets.

[18] The "letter book" of Charles Augustus Lamar was rediscovered in 1886 and includes numerous mentions of Trowbridge (sometimes called "Trow").

Lamar and Trowbridge were partners in selling bonds to support a freelance filibuster invasion of Cuba in hopes of bringing it into the Union as another slave state.

[20] The captain hired to sail the E. A. Rawlins to Africa and back would be paid with "two negroes out of every one hundred that the vessel may land.

[26] Trowbridge appears in the diary of U.S. secretary of the Navy Gideon Welles, in the entry of December 21, 1863: I received a large budget of Rebel letters captured onboard the Ceres.

Stanton read to me a letter which had been written in cipher, but which after two days' labor the experts had unlocked with the exception of a few words.

Certain allusions to Briggs, Cavnach, with a conviction on the part of Stanton that the letter was from Trowbridge, and also other points and names struck me as not entirely unfamiliar.

I did not entirely concur in their conclusions and told them the letters captured on the Ceres would furnish some light in regard to the persons alluded to, especially Trowbridge, Briggs, and C.; that I had not read the letters, but parts of several had been read to me and their publication would have a good effect; that they were with the Chief Clerk of the Navy Department, who was to copy and publish portions of them.

If, however, Trowbridge was to be arrested, it might be best to suspend publication for the present...Telegrams were sent to Marshal Murray at New York to arrest Trowbridge forthwith, and hold him in close custody, and to Admiral Paulding to place a gunboat in the Narrows and at Throg's Neck to stop all outward-bound steamers that have not a pass.

[26] Daniel Tompkins Van Buren and John Adams Dix handed down the orders regarding the transfer process.

[32] After the American Civil War, a witness testified to investigators for the U.S. Congress that N. C. Trowbridge was one of the brokers who helped them buy ships for cotton smuggling from the Confederate states.

Pitman" on charges of "shooting with intent to kill" because of "The extreme youth of the prisoner, and his uniform good character as a peaceable, quiet and industrious man.