National Washington Day Date in the current year: May 10, 2025

Washington is a state in the Pacific Northwest region of the United States, bordered by Oregon, Idaho, the Canadian province of British Columbia, and the Pacific Ocean. Named for the first American president, George Washington, it is often referred to as Washington State to avoid confusion with Washington, D.C.

Washington has no official state nickname; its unofficial nickname is the Evergreen State, due to the abundance of evergreen trees in the state’s forests. It was suggested in 1890 by Charles T. Conover of Seattle. Despite its popularity, the nickname has not been officially adopted. However, it is used on license plates, and a public liberal arts college in Olympia is called the Evergreen State College.

Before the arrival of Europeans, what is now Washington state was home to numerous indigenous tribes. According to anthropological estimates, there were at least 50 languages and dialects and 125 distinct tribes in the region during the pre-colonial era.

The first Europeans to land on the Washington coast were Spanish explorers Juan José Pérez Hernández in 1774 and Bruno de Heceta in 1775, who claimed for Spain the coastal lands from the mouth of the Quinault River to Prince William Sound. The region was further explored by Spanish, British, Russian, and American explorers, including the Lewis and Clark expedition.

In 1818, the United Kingdom and the United States signed a treaty allowing joint occupation of the Oregon Country in the Pacific Northwest, which included present-day Washington State. In 1846, Great Britain and the United States had a boundary dispute over Oregon, which they settled by signing the Oregon Treaty. In 1848, the Oregon Territory was created, comprising all of present-day Idaho, Oregon, and Washington, as well as parts of Montana and Wyoming.

Five years later, the Territory of Washington split from the Oregon Territory. It included present-day Washington and Idaho, and parts of Montana and Wyoming. In 1863, part of the Washington Territory split off to form the Idaho Territory. After passage of the Enabling Act of 1889, which allowed Montana, Washington, North and South Dakota to join the Union, Washington achieved statehood. It officially became the 42nd state on November 11, 1889.

In 2017, National Day Calendar created the National State Days project to celebrate the history, culture, and heritage of each U.S. state in the order in which they joined the Union. Celebrations begin on July 13 with National Delaware Day and are held each week thereafter, except during Thanksgiving and Christmas weeks, with National Washington Day falling on May 10. It should be noted that none of the National State Days established by National Day Calendar coincide with the actual admission anniversaries of the states.