The Montgomery County Courthouse in the center of downtown Conroe memorializes the remarkable history of one of the oldest counties in the state of Texas. Montgomery County is the third county created by the Republic of Texas, originally part of the Washington municipality. It was established through an act of the Congress of the Republic on December 14, 1837, in response to a petition by settlers on the east side of the Brazos River. Original boundaries of Montgomery County included present-day counties of Grimes, Walker, San Jacinto and a portion of Madison and Waller Counties. The town of Montgomery served as the first county seat. Three separate courthouses (two small log cabins and one two-story wood building) served county government until 1889 when the county seat was moved to Conroe after an election.
The home of Isaac Conroe served as a temporary courthouse until the first courthouse was constructed on this site in 1891. Red bricks, which were manufactured in Conroe, were used in the new courthouse and in the jail across the street. Many repairs and changes were made to the building, and in 1909 the exterior was plastered. In 1934, the county commissioners court voted to build a new, larger courthouse with a jail on the 4th and 5th floors. The present art deco-style courthouse was completed in 1936 during the economic prosperity
caused by the Conroe oil boom. In 1966, due to the growth of Conroe and Montgomery County, north and south wings were added. The courthouses of Montgomery County have been the center of political, civic and business activity since 1838.