Complex sentence: He also joined Delta Kappa Epsilon, as his father had, grandfather, and great-uncle had all been oarsmen at Yale, and his father was captain of the crew in 1898.
Split into simpler sentences: He also joined Delta Kappa Epsilon, as his father had. He, his father, grandfather, and great-uncle had all been oarsmen at Yale, and his father was captain of the crew in 1898.