Complex sentence: John Nix & Co. was one of the largest sellers of produce in New York City at the time, and was one one of the first companies to ship produce from Virginia, Florida, and Bermuda to New York.
Split into simpler sentences: John Nix & Co. was one of the largest sellers of produce in New York City at the time. Nix was one one of the first companies to ship produce from Virginia, Florida, and Bermuda to New York.