Complex sentence: On January 24,1766, the district of Northborough was established within neighboring Westborough; on August 23,1775, the district became a town; and on June 20,1807 part of neighboring Marlborough was annexed to Northborough.
Split into simpler sentences: On January 24,1766, the district of Northborough was established within neighboring Westborough. On August 23,1775, the district became a town, and on June 20,1807 part of neighboring Marlborough was annexed to Northborough.