Throughout its dynamic history, Princeton has transformed from a mere crossroads to a significant municipality, situated at the boundary between Somerset and Middlesex Counties along the historic thoroughfare connecting New York and Philadelphia, now known as Nassau Street. The establishment of Mercer County in 1838 marked a pivotal change, incorporating parts of West Windsor Township and portions of Montgomery Township to create Princeton Township. This expansion was further solidified in 1853 when additional land between the former Borough's southern boundary and the Delaware and Raritan Canal was integrated into Princeton Township.

In the early 19th century, New Jersey boroughs operated as quasi-independent entities within existing townships, lacking full autonomy. Princeton Borough received its charter in 1813, allowing it to operate under the governance of Montgomery and West Windsor Townships. Despite this initial arrangement, the borough remained tied to Princeton Township until the Borough Act of 1894, which mandated the establishment of singular school districts for each township. In response, Princeton Borough sought separation to form its own school district, highlighting a growing desire for self-governance.

Over the following decades, the two Princetons—Princeton Borough and Princeton Township—merged their public school systems, signaling a collaborative approach despite their differing governance structures. Minor boundary adjustments in 1928 and 1951 incorporated key facilities like Princeton Hospital and Princeton Regional High School into the Borough, reflecting the community's evolving needs.

A significant development occurred in 2011 when Princeton Borough and Princeton Township merged into a single municipality, streamlining governance and services for residents. This consolidation reflects the town's ongoing commitment to efficient local governance and the collective identity of its diverse community. As Princeton continues to navigate the complexities of governance, its rich history serves as a testament to the resilience and adaptability of its citizens.