Ulysses S. Grant was Commanding General of the Union Army during the American Civil War. In 1868, Grant was elected the 18th President of the United States and served two terms.
In the Timeless Universe
Grant originally planned to see the play "Our American Cousin" at Ford's Theatre with Abraham Lincoln, but was unable to. After a train malfunction that ruins his previous plans, Grant and Robert Todd Lincoln decided to attend the play.
During the play, Lucy Preston under the alias Juliet Shakesman, spills water on Grant. Lucy tries to make it look like an accident and apologizes. Grant gets up out of his seat goes to clean himself. The reason Lucy spilled the water was to try and make Grant leave for when Garcia Flynn, bursts through the door behind them and tries to kill both Lincoln and Grant. This is unsuccessful however, because Grant managed to come back to his seat before Flynn's assassination attempt.
When Flynn bursts through the door, he successfully assassinates Lincoln. Flynn takes a shot at Grant, but Lucy saves Grant by grabbing Flynn's arms. Robert Todd Lincoln and Grant try to fight Flynn off, but Flynn only flees after Lucy points her gun at him.
Ulysses S. Grant at Wikipedia