Complex sentence: In 1882 Chile refused US mediation in the War of the Pacific and 1885 as the US Navy occupied Colón, then Colombia, the Chilean government ordered its navy to occupy Panama City and not to leave until after the US troops evacuated Colon.
Split into simpler sentences: In 1882 Chile refused US mediation in the War of the Pacific. In 1885, as the US Navy occupied Colón, then part of Colombia, the Chilean government ordered its navy to occupy Panama City and not to leave until after the US troops evacuated Colon.