Complex sentence: A short time later he moved back to the United States, and formed a pin manufacturing company, Slocum and Jillson, which invented a "Machine for Sticking Pins into Paper", which is often wrongly believed to be the first stapler.
Split into simpler sentences: A short time later he moved back to the United States, and formed a pin manufacturing company, Slocum and Jillson. \\ made an invention, a "Machine for Sticking Pins into Paper", which is often wrongly believed to be the first stapler.