Complex sentence: The town was platted and incorporated after the arrival of the Montana, Wyoming & Southern Railroad in 1906, and it grew rapidly as American and foreign-born workers moved there, drawn by the promise of steady work.
Split into simpler sentences: The town was platted and incorporated after the arrival of the Montana, Wyoming & Southern Railroad in 1906. It grew rapidly as American and foreign-born workers moved there, drawn by the promise of steady work.