In the United States, Seo Jae-Pil attended the Harry Hillman Academy (Wilkes-Barre, PA) thanks to the help of John Welles Hollenback. He began to use the name "Philip Jaisohn" at that time. In 1890, he became the first Korean-American to acquire United States citizenship. He studied medicine at George Washington University, and was the first Korean to receive an American medical degree in 1892.