Longstreet, James (1821–1904), a United States and Confederate army officer. During most of the Civil War Longstreet commanded troops in Robert E. Lee's Army of Northern Virginia, rising to the rank of lieutenant general. He was engaged in most of the major battles of the war, including both battles of Bull Run, Antietam, Chancellorsville, Fredericksburg, Gettysburg, Chickamauga, and Knoxville. Longstreet was critical of Lee's plans at Gettysburg and contributed to the defeat by his delay in following orders.

Longstreet was born near Edgefield, South Carolina. He graduated from West Point in 1842 and served in the Mexican War and on the Texas frontier. He joined the Confederate army in June, 1861. After the war Longstreet moved to New Orleans and joined the Republican party. Later he settled in Georgia. He served as minister to Turkey, 1880–81, and United States marshal of Georgia, 1881–84.

Longstreet was unpopular in the South for many years for being a Republican and a friend of General Grant. From Manassas to Appomattox (1896) is his military autobiography.