The town was laid out by A. W. Casad in 1836 from Trenton, New Jersey, who gave his new town the name Trenton after the place he was from. The planned town was supposed to be built just north of the
Ohio and Mississippi Railroad in an area which is now called “Old Trenton”. However, the old town was abandoned as no one ever built in the lots they bought. In response to his failed venture, Mr. Casad returned to his hometown of Trenton, New Jersey. Mr. William Lewis, A. W. Casad's brother in law however didn't go back to New Jersey. Instead, he opted to stay and in 1818 built a farmhouse where the current town lies today. In 1853 Mr. Buckman built a railroad depot and even managed to get a post office to be established. However, his business partner Mr. Walker abandoned him, which made Buckman move out of the area. Buckman would eventually resettle in Iowa. On 14 May 1855, Alva Lewis refounded the town, and this time it stayed. Several more major additions were added to the town throughout the mid-1800s by multiple other people and companies. On 12 March 1856 and 11 June 1860 by William Lewis, 22 May 1856 and 2 July 1866 by Joseph Hanke, 12 June 1856 by Sanger Ramp & Co, and finally by Mathias Leonard and Sanger Kamp on 26 May 1868. On 16 February 1856, the town was chartered as a village with one Joseph P. Hanke as its mayor. By 1868 the town's south side had taken shape and no new major additions were added to that side of Town. On 20 September 1887, the Town was incorporated as a city. The town was now called the City of Trenton, which is the name it currently holds. In 1865 a coal mine was built in the town and in 1868 it reach full operational capacity. The mine was founded by Joseph Hanke, Wm. Schaeffer, and Johnson Buchter, with the mine eventually being bought out completely by Joseph Hanke. Hanke himself would be bought out by Consolidated Coal Company, which was based out of St Louis. Out of the 500 men in the town 300 were employed by the mine. On 27 February 1909, the south mine burned down and never reopened causing a huge financial blow to the town. The first church established in the town was St. John United Church of Christ in 1840. This would be followed by St. Mary Catholic Church in 1864, Grace Community Baptist Church in 1882, West Gate Baptist Church in 1961, and the New Life Christian Center in 1985. Many of these churches host humanitarian and education ventures. These include a food pantry held at West Gate Baptist Church and a preschool held at St. John United Church of Christ. In 1886 a school was built in the town after the first one was destroyed in a fire. In 1957 a merger of
New Baden,
New Memphis, and Trenton formed the Wesclin School District #3 with a high school being built in 1972 along Route 161 exactly 2.5 miles between New Baden and Trenton. A new high school was built in 2014. ==Geography==