[6] The city was named in commemoration of the Battle of Princeton in the American Revolutionary War.

[8] The Herbert Cain and Corah Brantley Casteel House and Leo Ellis Post No.

22, American Legion Building are listed on the National Register of Historic Places.

U.S. Route 65 passes through the east side of the city, leading south 24 miles (39 km) to Trenton and north 13 miles (21 km) to Lineville, Iowa.

U.S. Route 136 passes through the north side of Princeton, briefly joining US 65 but leading east 33 miles (53 km) to Unionville and southwest 28 miles (45 km) to Bethany.

Princeton has a hot-summer humid continental climate (Köppen Dfa).

Summers are often hot and humid whereas winters are dry with days averaging above freezing in all months, which means sparse snow cover in spite of the cold overnight temperatures.

41.9% of all households were made up of individuals, and 22.4% had someone living alone who was 65 years of age or older.

42.9% of all households were made up of individuals, and 30.1% had someone living alone who was 65 years of age or older.