Complex sentence: She returned to live in New York City in WWII and after her husband's death in 1942 spent years collating their collection and associated papers and donated many artifacts to various museums and the papers to the New York Library.
Split into simpler sentences: She returned to live in New York City during World War II and after her husband's death in 1942 spent years collating their collection and associated papers. She donated many artifacts to various museums and the papers to the New York Library.