Complex sentence: It was built by the B&L to connect to the Lexington and Arlington Railroad after its 1870 acquisition, and a branch was later added, extending it to form the Fitchburg Cutoff.
Split into simpler sentences: It was built by the B&L to connect to the Lexington and Arlington Railroad after its 1870 acquisition. A branch was later added, extending it to form the Fitchburg Cutoff.