Complex sentence: The company was in such bad financial status, but Lamont fixed it and the company changed its name to Lamont, Corliss, and Company and was partners with his brother-in-law, Corliss.
Split into simpler sentences: The company was in a bad financial status, but Lamont fixed it, and the company changed its name to Lamont, Corliss, and Company. He was partners with his brother-in-law, Corliss.