The C-SPAN network's core programming is live coverage of the U.S. House and Senate, with the C-SPAN channel emphasizing the United States House of Representatives. Between 1979 and May 2011, the network televised more than 24,246 hours of floor action. C-SPAN2, the first of the C-SPAN spin-off networks, provides uninterrupted live coverage of the United States Senate. With coverage of the House and Senate, viewers can track legislation as it moves through both bodies of Congress. Important debates in Congress that C-SPAN has covered live include the Persian Gulf conflict during 1991, and the House impeachment vote and Senate trial of President Bill Clinton in 1998 and 1999 as well as the impeachment proceedings of President Trump in 2019 and 2020. When the House or Senate are not in session, C-SPAN channels broadcast other public affairs programming and recordings of previous events.