Who is John Galt?

John Galt is a fictional character in Ayn Rand's novel "Atlas Shrugged." The book's opening line is "Who is John Galt?" The line is repeated throughout "Atlas Shrugged."

"Atlas Shrugged" reveals John Galt to be the son of a garage mechanic from Ohio who left home when he was 12. He begins attending college at age 16 with a double major in physics and philosophy. After graduation, Galt becomes an engineer and designs a motor that's powered by static electricity. He later organizes a strike of the world's creative leaders. The strike becomes a mystery to uncover for the book's protagonist, Dagny Taggart.