Conroe, the county seat of Montgomery County, is on Interstate Highway 45 at the junction of the Union Pacific and the Burlington Northern Santa Fe railroads, seven miles southeast of Lake Conroe in central Montgomery County. In 1881 Houston lumberman Isaac Conroe established a sawmill on Stewarts Creek two miles east of the International-Great Northern Railroad's Houston-Crockett line on a tract of land in the J. G. Smith survey, first settled in the late 1830s. A small tram line connected the mill to the I-GN track, but Conroe soon transferred his operations down the tracks to the rail junction, where his new mill became a station on the I-GN. In January 1884 a post office was established at the mill commissary, and, at the suggestion of railroad official H. M. Hoxey, the community took the name Conroe's Switch, in honor of the Northern-born, former Union cavalry officer who founded it and served as its first postmaster; within a decade the name was shortened to Conroe.
In the mid-1880s the Gulf, Colorado and Santa Fe Railway extended its Navasota-Montgomery spur eastward through the town, which thus became the only junction of major rail lines in the county. Conroe Mill School was established in 1886, and not long afterward the community's first Black school was founded at Madeley Quarters, south of town. A lumber boom beginning in the late nineteenth century in the Piney Woods of eastern and central Montgomery County attracted scores of settlers to Conroe. By 1889 the population had climbed to an estimated 300. In that year Conroe replaced Montgomery as county seat. A residence donated by Isaac Conroe served as a temporary courthouse until a permanent brick structure could be erected in 1891. By the early 1890s Methodist, Presbyterian, and Baptist congregations were organized in the town; they initially shared a single house of worship. Simultaneously, Black residents founded Baptist and African Methodist Episcopal congregations.
By 1892 the community had become a shipping center for lumber, cotton, livestock, and bricks, and had five steam-powered saw and planing mills, several brickyards, a cotton gin, a gristmill, several hotels and general stores, and a population of 500. The Conroe Independent School District was established in 1892, combining twelve nearby common school districts, and within a year a second white school was established in the town. By 1896 the community's first weekly newspaper, the Courier, had been founded.
During the late nineteenth and early twentieth centuries Conroe briefly shipped local tobacco. In 1900 a four-room schoolhouse for white pupils of all grades was constructed, and the local Black school was transferred to the building abandoned by the whites. Since 1900 most Black residences have been in a district on the southeastern edge of town. In 1902 the town's first white high school class graduated. Three years later a public school library was established. In April 1903 a private coeducational vocational school for Blacks was founded by Dr. Jimmie Johnson on a seven-acre tract in northeast Conroe and quickly began to attract students from around the state. Funds for support of the institution were solicited from Black churches, conventions, and organizations throughout the nation; local white residents also made financial contributions to the school and provided its students with employment in their homes and businesses. By the end of World War I the college's enrollment had climbed above 400.
By 1900 Conroe was Montgomery County's largest community. It was incorporated in 1904 with a population of 1,009, and its first mayor and city council were elected the following year. In 1906 the first electric lighting appeared in the town when an electrical generating plant was constructed on nearby Stewarts Creek. About 1910 the community's first Catholic church was constructed, and the first Black public school was established. Over the next two decades the Conroe Independent School District was expanded to encompass twenty-five square miles. Some 617 pupils were enrolled in the district by 1913. Six years later the first Black high school in Conroe was established.
The prosperity of the local agriculture and timber industries in the early twentieth century enabled Conroe to continue its rapid early growth despite severe fires in 1901 and 1911, which destroyed much of the business district near the courthouse square. Southwest of town in 1913 the Delta Land and Timber Company established one of the most extensive milling operations in the South; the company eventually employed 700 people. In addition to its many churches and schools, by 1914 Conroe had two banks, five grocery and hardware stores, two dry-goods stores, two drugstores, a cotton gin, a waterworks, a planing mill, numerous sawmills, box factories, cross-tie mills, two weekly newspapers, the Courier and the Montgomery County Times, and an estimated population of 1,374. The population continued to climb for the next several years, reaching an estimated 1,858 in the mid-twenties and an estimated 2,457 by 1931.
A sanitarium was established in Conroe in 1920. The community acquired its first fire truck in 1921, and two years built its first fire station. In 1922 the courthouse grounds became the scene of communal violence when a Black mill worker accused of rape was staked to a pole and burned to death. In the mid-1920s the Dr Pepper Company opened a soft-drink plant in the community. In 1925 the Conroe Independent School District was enlarged to its present size, 330 square miles, with the inclusion of fifteen rural common schools and 600 additional pupils scattered through central and southern Montgomery County. Children from discontinued schools were transported in private buses to schools in Conroe.
After years of sustained growth, the town's prosperity was threatened in the late 1920s by the dwindling of the improperly managed local timber supply. Then in 1930 the spreading effects of the Great Depression struck Montgomery County, drastically curtailing lumber production and forcing many mills to close. In November 1930 Conroe's only bank abruptly failed and pushed many residents and institutions into financial doldrums for many years. Faced with precipitous declines in revenue, Conroe's schools struggled to complete full terms. But the community's fortunes began to improve on December 13, 1931, when George W. Strake discovered oil seven miles southeast of town, thus marking the opening of the Conroe oilfield and triggering an oil boom in the county. Within weeks the local economy had revived, as many petroleum wholesalers, retailers, and service companies and thousands of workers entered the town. By 1933 the population was an estimated 5,000, and eighty-four business were reported in the community. The Conroe school district, rescued from financial distress by the discovery of oil within its boundaries, became one of the wealthiest in the state, and its enrollment began to grow rapidly. A new Black high school was built in 1933, and a new white elementary school and a junior high were soon constructed. A community center and a swimming pool were completed by the district in the early 1940s.
The oil revenues and population influx of the 1930s lent Conroe a boomtown atmosphere. It briefly claimed more millionaires per capita than any other town in the United States. During the early 1930s streets were paved for the first time, and U.S. Highway 75 was extended through the town. The thirty-seven-room State Hotel was completed in 1933. The ornate Crighton Theater was erected on the courthouse square in 1935. In 1936 a new courthouse was constructed, and two years later a county hospital was completed not far from the courthouse square. That year the population surged to an estimated 10,000, but it soon began to subside as production in the Conroe oilfield crested and began a gradual decline. By 1941 the population stood at an estimated 4,624.
During World War II the town's lumber industry revived, but it never regained its earlier preeminence and lapsed into a steady decline after 1950. Its former position was increasingly assumed by chemical firms, including a carbon black factory (see CARBON BLACK INDUSTRY) and a recycling plant, established after the oil discovery. The Montgomery County Airport, three miles northeast of town on Farm Road 1484, was constructed during the war as a military facility but since 1945 has served as a local airfield. In 1946 the Montgomery County Library was established in Conroe. A new Black high school constructed in the early 1950s remained the pride of the Black community until Conroe's schools were desegregated in 1968. By 1952 Conroe had a population estimated at 7,313 and 340 businesses. The population climbed to an estimated 9,192 in 1961 and 11,969 in 1972.
With the construction of Interstate Highway 45, increasing numbers of Houstonians took up residence on the margins of Conroe. Lake Conroe was impounded in the late 1960s and early 1970s, seven miles northwest on the West Fork of the San Jacinto River, further stimulating local growth. In addition to the familiar lumber and petrochemical concerns, a number of new manufacturing and engineering firms have been established in Conroe. The population reached an estimated 18,034 by 1982. Conroe Independent School District had an enrollment of 8,873 in 1971 and 15,112 by 1976. In 1980 the district employed 1,200 teachers in twenty-eight schools. Conroe Normal and Industrial College has struggled for survival since the depression; by 1980 enrollment had been reduced to 176. In the 1980s Conroe had two hospitals, a nursing home, ten medical clinics, nineteen churches, three radio stations, a television station, a cab company, a new sewage treatment plant, and a newspaper named the Daily Courier. The population of Conroe grew to 27,610 by 1990, 43,617 by 2000, and reached 63,322 by 2015.