Complex sentence: The regiment was organized in New York City in May 1861 as a Zouave regiment, known for its unusual dress and drill style, by Colonel Elmer E. Ellsworth, a personal friend of U.S. President Abraham Lincoln.
Split into simpler sentences: The regiment was organized as a Zouave regiment, known for its unusual dress and drill style, in New York City in May 1861 by Colonel Elmer E. Ellsworth. Ellsworth was a personal friend of U.S. President Abraham Lincoln.