Barack Obama (born August 4, 1961) Honolulu, Hawaii, is an American politician, lawyer, and author who served as the 44th president of the United States from 2009 to 2017. A member of the Democratic Party, Obama was the first African-American president of the United States. He previously served as a U.S. senator from Illinois from 2005 to 2008 and as an Illinois state senator from 1997 to 2004. Obama's most significant legacy is generally considered to be the Affordable Care Act (ACA), provisions of which went into effect from 2010 to 2020. He became the fourth U.S. president to be awarded the Nobel Peace Prize and the third to become a Nobel laureate while in office.