Complex sentence: After arriving in Charleston in December 1773, Salvador at once entered into the American cause, and became close friends with the leaders of the Revolution in the South, including Pinckney, Rutledge, Drayton, Laurens, and Hammond.
Split into simpler sentences: After arriving in Charleston in December 1773, Salvador at once entered into the American cause. He became close friends with the leaders of the Revolution in the South, including Pinckney, Rutledge, Drayton, Laurens, and Hammond.