Smithfield, in north central Tarrant County, was probably established before 1870 and was originally called Zion. A post office opened there in 1878. In 1887 the St. Louis and Southwestern Railway built through the area a quarter mile south of Zion, and a new section of the community grew up near the tracks. This new development siphoned away population and businesses from the older section, which eventually was abandoned.
The new railroad settlement was called Smithfield, for Eli Smith, who had donated land for a church and cemetery in Zion. Smithfield initially flourished as a shipping point for the products of area farms and ranches. Though the town suffered a bad fire in 1890, by 1900 it had a population of 137, and the local school employed three teachers and enrolled 156 students from the area. The population of Smithfield remained at about the same level through the 1930s, but it began to grow around World War II because of the boom in war-related employment in nearby Fort Worth.
By the late 1940s Smithfield reported 350 residents and eight businesses. After a bitterly contested campaign and election, however, nearby North Richland Hills annexed Smithfield in 1958. The Smithfield name survives in several local institutions, including a middle school, and on historical markers at the Smithfield cemetery, Masonic lodge, and two churches.