Mr. Ameur,
The Life and Memoirs of Comte Regis De Trobriand, by his daughter Marie Caroline Post (New York: E. P. Dutton and Company, 1910) is about a famous general, Philip Regis Denis de Keredern De Trobriand. At Gettysburg (July 1863) he was a colonel leading a brigade in the Union Third Corps. I have a copy of some letters (in French) that he wrote on that battle and would be pleased to mail them to you, if you are interested.
Here is a description of him from Boatner's Civil War Dictionary:
1816-1897. The son of the Baron de Trobriand, "he engaged in duels, wrote poetry, and published a novel" before coming to America on a trip. While in this country he married an heiress and settled down, becoming an American citizen and serving as colonel of the "Guards Lafayette" of the New York State Militia. He was commissioned colonel of the 55th New York on 28 August 1861 and transferred to the 38th New York on 21 December 1862. Continuing in the Army of the Potomac, he held brigade level commands through November 1863. He was appointed Brigadier General, US Volunteers on 5 January 1864 and held various other brigade commands through the end of the war. He also led the Third Division, Second Corps for periods during 1864 and 1865. He was brevetted a Major General on 9 April 1865 for the closing campaign of the war. He continued in the regular army, retiring in 1879 as colonel of the 13th U.S. Infantry. He succeeded his father to the title in 1874. His Quatre Ans de Campagnes a l'Armee du Potomac (1867-1868) is one of the better histories of the war.