Who was the 44th President of the United States?

Barack Obama was the 44th President of the United States, serving two terms from January 20, 2009, to January 20, 2017. His presidency marked a significant moment in American history, as he was the first African American to hold the office. During his time in office, he implemented policies that focused on healthcare reform, economic recovery, and climate change. His notable achievements include the Affordable Care Act, also known as "Obamacare," aimed at expanding healthcare coverage to more Americans.

Understanding the context of presidential terms and major contributions is essential for a comprehensive grasp of U.S. history. Each of the other individuals listed served at different times and had unique impacts on the country, but they do not hold the title of the 44th President.