Complex sentence: Pratt recognized the potential replacement of whale oil with petroleum ("natural oil") distillates for lighting purposes, and he became a pioneer of the petroleum industry as new wells were established in western Pennsylvania in the 1860s.
Split into simpler sentences: Pratt recognized the potential for replacement of whale oil with petroleum ("natural oil") distillates for lighting purposes. He became a pioneer of the petroleum industry as new wells were established in western Pennsylvania in the 1860s.