Complex sentence: Trout was behind the microphone for many of broadcasting's firsts: first to report live congressional hearings, to transmit from a flying airplane, and by some definitions the first to broadcast a daily news program and to create the news anchorman role.
Split into simpler sentences: Trout was behind the microphone for many of broadcasting's firsts. He was the first to report live congressional hearings, first to transmit from a flying airplane, and by some definitions the first to broadcast a daily news program and to create the news anchorman role.