The Open Door Policy in Lincoln's White House.

[AussieMick]

I’m sure he didn’t imagine being killed in a theater either.

Bill, I think it would have been interesting as to what might have happened if the Lincolns had gone with Tad to Grover's Theatre that night. According to Leonard Grover, Booth had secured tickets to the play at Grover's just in case Mary and Abraham had chosen that theater. Booth's tickets were for the box adjoining the box where the Lincoln party would have been seated. I do not know whether it's possible to jump to the stage from the boxes at Grover's. Possibly Booth's plan of escape would have been different had the planned assassination occurred at Grover's.

Booth (apparently) knew the 'Our American Cousin' quite well and waited for the funny line by Harry Hawk. He could have used a similar moment in “Aladdin! or His Wonderful Lamp' ... I'm sure that there must be a moment in that play where theres a big puff of smoke from the lamp and the audience wouldnt have been surprised by a Bang! followed by Booth leaping onto the stage.