Complex sentence: Construction of the Meriden and Waterbury Railroad commenced in 1887 and finished the following year, when the M&W Railroad merged with the Meriden and Cromwell Railroad to form the Meriden, Waterbury, and Connecticut River Railroad.
Split into simpler sentences: Construction of the Meriden and Waterbury Railroad commenced in 1887, and finished the following year. Then, the M&W Railroad merged with the Meriden and Cromwell Railroad to form the Meriden, Waterbury, and Connecticut River Railroad.