National Pennsylvania Day Date in the current year: July 20, 2025

Pennsylvania is a state in the Appalachian, Great Lakes, Mid-Atlantic, and Northeastern regions of the United States. It is bordered by Delaware, Maryland, New Jersey, New York, Ohio, West Virginia, and the Canadian province of Ontario.

The territory that is now Pennsylvania has been inhabited for thousands of years. When European colonization of the New World began, the region was dominated by at least two major Indigenous tribes: the Lenape and the Susquehannock.

In the 17th century, the Netherlands, Sweden, and England all claimed lands on both sides of the Delaware River as part of their North American colonies. The Dutch established the colony of New Netherland in 1614, and the Swedes established New Sweden in 1638. In 1655, the Dutch conquered New Sweden and incorporated its territory into New Netherland, which included parts of present-day Pennsylvania.

British colonization of the region began in 1664. Though there was some fighting between the Netherlands and England over North American territories, the Treaty of Westminster of 1674, which ended the Third Anglo-Dutch War, transferred control of New Netherland to England.

In 1681, Quaker leader William Penn was granted a land charter by King Charles II, who owed a debt to Penn’s father, Admiral and politician Sir William Penn. Penn wanted to name the colony New Wales or Sylvania, from the Latin word for “woods”. Ultimately, the king named it Pennsylvania (“Penn’s Woods”) in honor of Admiral Penn. Before the American Revolution, the Province of Pennsylvania was known for its political and religious tolerance, as well as its relatively peaceful relations with Native American tribes.

During the American Revolution, Pennsylvania was the site of many pivotal events, including several major battles and the First and Second Continental Congresses. The Declaration of Independence and the United States Constitution were both discussed, adopted, and signed at Independence Hall in Philadelphia.

The U.S. Constitution was signed and sent to the thirteen states for approval on September 17, 1787. Delaware became the first state to ratify the Constitution on December 7, and Pennsylvania followed on December 12, becoming the second state to officially join the Union. While Delaware ratified the Constitution unanimously, Pennsylvania approved the measure 46–23.

National Pennsylvania Day is part of the National State Days project, which was launched by National Day Calendar in 2017 to celebrate all states in the order in which they joined the Union. Celebrations start on July 13 with National Delaware Day and continue a week later with National Pennsylvania Day. Due to the manner in which National Day Calendar celebrates the states, National Pennsylvania Day does not coincide with Pennsylvania’s actual admission anniversary.