San Juan Island National Historic Park is a National Park located on the southern section of San Juan Island. Here you can learn why in 1859 that the United States and Great Britain nearly went to war over a dead pig! A visitor center also displays four cases of archaeological objects where you can learn more about the history of San Juan Island. San Juan Island National Historical Park consists of two distinct units, American Camp and English Camp, which together comprise 2,064 acres. The park includes over six miles of publicly accessible shoreline.