Moore never really knew her father, John Milton Moore. He had a nervous breakdown just before she was born and was committed to a mental institution in Missouri. A few years later, Marianne's mother, Mary Warner, packed up their things and moved her and her brother to Pennsylvania (source).
Henry Wadsworth Longfellow's old house is also located in Cambridge, MA, just like his grave and the Harvard glass flowers. It's now a popular venue for concerts and poetry readings (source).
Moore was a well-known baseball fanatic, even throwing the first pitch for the Yankees' 1968 season. She often mentions baseball in her poems (source).
In her later years, Moore took to wearing a tricorn hat and cape at public events (source).