Letter book containing copies of Herron's correspondence (Jan.-June 1864), chiefly letters sent while in command of the U.S. Forces on the Rio Grande at Brownsville, Texas. Herron writes to his military superiors, officials in Mexico, and U.S. diplomatic officials in California and Matamoros, often discussing affairs on the Texas-Mexico border. Correspondents include Manuel Ruiz, Gov. of Tamaulipas; M.M. Kimmey, U.S. vice consul, Monterrey; Brig. Gen. Charles P. Stone; and Col. Juan N. Cortinas, military governor of Matamoros. Probably maintained by Orderly Sergt. James M. Beynon whose name appears on a label inside front cover.