James FitzHugh was a Continentalist Senator from Durango who was elected in the 1857 Mexican elections and subsequently re-elected for several terms. Sobel describes him as one of the new, attractive Continentalist leaders who rose to power after the Rocky Mountain War to regain control of the Senate and deny a second term to President Hector Niles. Sobel also states that FitzHugh was an associate of former President Pedro Hermión, though he does not specify the nature of their association.
FitzHugh owed his election to wealthy San Francisco businessman and Kramer Associates founder Bernard Kramer. When Kramer went to Mexico City in March 1867 to gain government support for his plan to build a canal in Guatemala, FitzHugh was one of the men he met with. FitzHugh spent the next several months lobbying Niles' successor, Arthur Conroy, on Kramer's behalf.
Although Sobel does not specifically say so, FitzHugh was presumably one of the Continentalist Senators who opposed the Conroy reforms in the 1860s and the Kinkaid reforms in the 1870s, also at Kramer's behest.