Complex sentence: Having made his fortune in the railroad business, James Jerome Hill was a great patron of the arts and all of his heirs were exposed to and owned great collections, presumably having a strong influence on Beard's interests in the arts and beauty.
Split into simpler sentences: Having made his fortune in the railroad business, James Jerome Hill was a great patron of the arts. All of of his heirs were exposed to and owned great collections, presumably having a strong influence on Beard's interests in the arts and beauty.