Muldoon is on Farm Road 154 nine miles north of Flatonia in southwestern Fayette County. It is located on a grant of land originally made in 1831 to Father Michael Muldoon, who was the curate for Stephen F. Austin's first Texas colony. The town was not platted until 1886, when the Waco branch of the San Antonio and Aransas Pass Railway extended its line between West Point and Flatonia. A post office was established in 1888. By 1890 the business community was the center of a voting precinct and included a store, a saloon, a hotel, a blacksmith shop, and a physician. Local quarries produced fuller's earth and stone used in the construction of the Galveston jetties. Due to the poor agricultural characteristics of the soil and the proximity of other communities Muldoon grew slowly; it reached a peak population of 200 with eight businesses in 1943. During the 1980s three businesses and the post office remained to serve fewer than 100 residents. In 1990 through 2000 the population was ninety-eight.