National Pennsylvania Day is observed every July 20 to recognize Pennsylvania as the second state to ratify the United States Constitution and join the Union. Established by National Day Calendar, this holiday is part of the National State Days project, which celebrates states in the order they joined the Union. Pennsylvania, known for its political and religious tolerance, played a significant role during the American Revolution, hosting pivotal events such as the signing of the Declaration of Independence and the U.S. Constitution at Independence Hall in Philadelphia. The day highlights the state's historical significance, especially its early relationships with Indigenous tribes like the Lenape and Susquehannock, and its colonial history under Dutch, Swedish, and British control. Celebrations typically include educational activities and events that honor Pennsylvania's rich heritage and contributions to the nation.