Original: In 1995, Time magazine selected him as the Person of the Year for his role in leading the Republican Revolution in the House, ending 40 years of the Democratic Party being in the majority.
Simplified: He was speaker of the House of Representatives from 1995 to 1999. He is known for bringing in the "Republican Revolution" in the House because his political party, the Republican Party, or GOP, after 40 years of the Democratic Party dominating Congress.