The play that night

The play Our American Cousin was produced by American actress Laura Keene (1826-1873) and premiered in 1858 at her theater in New York. It was a farcical comedy written by Tom Taylor (1817-1880) about awkward American Asa Trenchard (played by Harry Hawk) meeting his aristocratic relatives when he goes to England to claim an inheritance. Its most famous performance came 7 years later on the night of April 14, 1865, at Ford's Theater in Washington, D.C. The dialog just before the fateful moment follows:

Asa: You crave affection, you do. Now, I've no fortunes, but I'm spilling over with affections, which I'm ready to pour out all over you, like apple sass, over roast pork.
Mrs. M: Mr. Trenchard, will you please recollect that you are addressing my daughter, and in my presence.
Asa: Yes I'm offering her my heart and hand just as she wants them, with nothing in 'em.
Mrs. M: Augusta, dear, to your room.
Augusta: Yes Ma, the nasty beast.
Mrs. M: I am aware, Mr. Trenchard, that you are not used to the manners of good society, and that, alone, will excuse the impertinence of which you have been guilty.
Asa: Don't know the manners of good society, eh? Well, I guess I know enough to turn you inside out, old gal - you sockdologizing old man-trap.

Loud laughter erupted, as he knew it would, when assassin John Wilkes Booth entered the state box at the theater and fired his single-shot pistol into the back of the president's head. The performance, which had stopped briefly after 8:45pm to honor Lincoln's arrival, came to an abrupt halt at 10:15pm, and Keene - who was poised to take the stage - is said to have rushed to the president's box and cradled his head in her lap.

After the assassination, the theater was closed and its owner briefly imprisoned until he could be cleared of complicity. Our American Cousin, however, continued in popularity and one of its characters, Lord Dundreary, featured in future spin-offs and added a new word to the language - a word now as obscure as "sockdologizing."