William King was an American politician who served as the first Governor of the state of Maine from 1820 to 1821. He played a significant role in the separation of Maine from Massachusetts, which was a pivotal moment in the state's history. King was a member of the Democratic-Republican Party and was known for his leadership during this transitional period. Before becoming governor, King was involved in various public service roles, including serving in the U.S. House of Representatives. His tenure as governor was marked by efforts to establish a stable government and promote economic development in the newly formed state. After his term, he continued to be active in politics and public affairs.