During the American Civil War, the grounds of the Ellipse and the incomplete Washington Monument were used as corrals for horses, mules, and cattle, and as camp sites for Union troops.

In 1865, the Nationals hosted a baseball tournament with the Philadelphia Athletics, for which viewing stands were built and admission was charged.

On August 10, 1933, the Ellipse was transferred to the National Park Service, the legal successor of three federal commissioners appointed by the President under an act of July 16, 1790, which directed initial construction.

In 1942, during World War II, the National Park Service granted permission for the construction of barracks as a special emergency wartime measure.

The temporary barracks were erected on the south side of the Old Executive Office Building and the entire First Division Monument grounds.

Immediately prior to the January 6 United States Capitol attack,[6] President Donald Trump delivered a speech on the Ellipse to his supporters gathered at a "Save America rally" to challenge the result November 2020 presidential election.

[7] The speech was followed by mass violence, with supporters storming the United States Capitol in an attempt to prevent the certification of President-elect Joe Biden as the winner of the election.

[8] On October 29, 2024, in the closing days of the 2024 Presidential election campaign, Vice President Kamala Harris held a rally on the Ellipse, delivering a speech to an estimated 75,000 attendees.

Under the auspices of the National Park Service, the Capital Alumni Network and a number of neighborhood and military sports leagues play softball and flag football games on the grounds of the Ellipse.