The origin of Duncanville can be traced as far back as 1840, with the community's beginning as a small settlement. It was not until some forty years later, with the construction of the Chicago, Texas and Mexican Central Railroad connecting Dallas and Cleburne that Duncanville began to emerge as a town. The coming of the railroad to Duncanville changed the community. The railroad line connecting Dallas to Cleburne was to be completed not later than April 15, 1881. With time running short to complete the railroad on time, a shortened method of railroad construction was adopted at an open field owned by James R. Horne and G.H. Finley. Doing this allowed the railroad to arrive in Cleburne two hours ahead of the deadline and a switching station was later built in the open field. It was called Duncan switch.

In 1881, Charles Nance arrived by train at Duncan Switch to visit his sister, Mrs. William Horne. Finding the area much to his liking and envisioning a bright future for this part of Dallas County, Mr. Nance made the decision to stay in this area. He formed a partnership with Chris Horne, for fifty dollars purchased a lot from G.H. Finely, and built the first building, Nance Brothers, at Duncan Switch.

In August of 1881, Nance forwarded a petition to the Post Office Department in Washington, D.C. to establish a post office. Residents at that time were receiving their mail at post offices in Cedar Hill, Wheatland, or Jim Town. His application was returned with a notation to choose a different name because there was already a post office in Jasper County, Texas with the name of Duncan. There had been individuals in the community who had refused to sign Nance's original petition and many others who were hard to convince, so he simply added "ville" to Duncan, so it now read Duncanville. The petition was returned to Washington and, in early October 1881, he received the order to open the new post office under the name Duncanville.

With Mr. Nance as the first postmaster, the post office opened in the general store and the first mail bags were received October 1, 1882.The growth and development of Duncanville occurred along the railroad tracks. In 1883, a large two-room depot was constructed immediately adjacent to the railroad tracks. Over time, businesses began emerging along the east side of the tracks. The first businesses to be established were the cotton gin, two general stores, and a doctor's office.