Complex sentence: Much of Velasco, first owned by John A. and William H. Wharton, was later sold to an agent of the English Rothschild family, who planned to establish a great seaport at the site.
Split into simpler sentences: Much of Velasco, first owned by John A. and William H. Wharton, was later sold to an agent of the English Rothschild family. They planned to establish a great seaport at the site.