See Mr. Lincoln's City by Richard M. Lee published by EPM publications. He died early the next day at the Peterson House across the street. The theater, still active, has been restored and is open for self-guided tours. A museum contains artifacts relating to assassination. Watch out for large groups of school kids in the mornings during the spring and early summer.
Waits can last up to an hour.
Theater is sometimes closed for matinee performances and rehearsals, most often on Thursdays and Sundays. Museum continues open during those times. The Peterson House is directly across the street from the theater. See restored rooms where Mary Lincoln waited, the cabinet met and Lincoln died. This tour goes quickly and is self-guided.