Complex sentence: Beck's mother was a member of the Comanche tribe, accounting for Beck's long term interest in American Indian matters: he was, for example, one of the earliest members of the National Museum of the American Indian.
Split into simpler sentences: Beck's mother was a member of the Comanche tribe, accounting for Beck's long term interest in American Indian matters. He was, for example, one of the earliest members of the National Museum of the American Indian.