John F. Kelly is a retired United States Marine Corps general who served as the White House Chief of Staff under President Donald Trump from July 2017 to January 2019. He was born on May 11, 1950, in Boston, Massachusetts, and had a distinguished military career, including commanding U.S. Southern Command. Before his role in the White House, Kelly was the Secretary of the Department of Homeland Security, where he focused on immigration and border security issues. He is known for his leadership style and experience in military operations, which influenced his approach to managing the White House staff.