He spent the next year and a half in Federal hands at Johnson's Island and Fort Warren. He was recommended for parole soon after capture, but former U.S. Secretary of War Simon Cameron recommended against it, citing Trimble's expert knowledge of northern railroads. In March 1865, Lt. Gen. Ulysses S. Grant ordered Trimble to be sent to City Point, Virginia, for exchange, but by the time he reached there, Robert E. Lee's army was already retreating in the Appomattox Campaign. Trimble was finally paroled in Lynchburg, Virginia, on April 16, 1865, just after Lee's surrender. After the war, Trimble, equipped with an artificial leg, returned to Baltimore, Maryland, to resume his engineering work. He died in Baltimore and is buried there in Green Mount Cemetery, arguably the most famous Maryland resident who fought for the Confederacy. In 1849, Trimble built Baltimore's historic 1849 President Street Station. The oldest big city train station in America, it was restored in 1997 to serve as the Baltimore Civil War Museum. Isaac Trimble was played by actor W. Morgan Sheppard in the movies "Gettysburg" and "Gods and Generals".