Complex sentence: In 1899,17-year-old Jack "Cowboy" Kelly is one of many struggling newspaper hawkers in New York City, selling copies of the "New York World" on the streets of Manhattan.
Split into simpler sentences: In 1899,17-year-old Jack "Cowboy" Kelly is one of many struggling newspaper hawkers in New York City. He and his fellow "newsies" sell copies of the "New York World" on the streets of Manhattan.