Many Jewish communities in the United States mark the last day of Passover as the end of a Jewish holiday that celebrates the deliverance of Jewish people from slavery in Egypt. Passover is also known as Pesah, Pesach, or the Feast of Unleavened Bread.

Many Christians celebrate Jesus Christ's resurrection on Easter Sunday. The Easter date depends on the ecclesiastical approximation of the March equinox.

Easter Monday is the day after Easter Sunday. It is not a federal holiday in the United States of America (USA). Some Easter traditions continue on the Easter Monday, such as the egg rolling race at the White House.

National Tartan Day is a US observance on April 6 each year. It commemorates the Scottish Declaration of Independence, from which the American Declaration of Independence was modelled on. It also recognizes achievements of Americans of Scottish descent.

Librarians across the United States celebrate National Library Workers’ Day (NLWD) on the Tuesday of National Library Week, held in April every year.

Many United States residents mark Tax Day as the deadline to file their income tax details to the Internal Revenue Service (IRS). The date is usually on or around April 15. However, this deadline may be extended to accommodate holidays or extreme weather conditions.

The Boston Marathon is held in the city of Boston, Massachusetts on Patriot's Day, the third Monday of April. First held in 1897, it is the world's oldest annual marathon.