Rock Island was an early settlement on the Brazos River near Farm Road 1736 and west of present State Highway 6, six miles north of Hempstead and fifteen miles south of Washington-on-the-Brazos. Conflicting local traditions place the Rock Island community on both the west bank of the Brazos in Washington County and on the east bank in Austin(now Waller) County. Marshy terrain in the area today indicates that the Brazos River may have changed its course during Rock Island’s existence. Map location (above) approximate.
The Rock Island settlement grew from a plantation named Rock Island, owned by Jared E. Groce’s granddaughter, Barbara Groce Clarke. This plantation was north of the Groce family’s Bernardo Plantation and three miles northwest of their Liendo home. Rock Island was named by an early settler, Amos Gates, who noted the small island in the Brazos opposite the site. Near Barbara Clarke’s plantation a general store, an inn, a cotton gin, and a blacksmith shop attracted the first concentrated population in the area. Rock Island’s growth slowed in 1837 when it lost a county seat election to Washington. A ferry and the establishment of Rock Island Academy contributed to Rock Island’s prosperity.
By 1839 a road linked Rock Island to Washington and to the Houston road. By 1846 a post office had been established at Rock Island or nearby. In June 1849 Rock Island had a post office of its own. Despite Washington’s growing share of steamboat traffic, Rock Island prospered until the arrival of rail transportation in the area. Washington’s refusal to pay the Houston and Texas Central Railway a subsidy to cross the Brazos at Rock Island caused Rock Island’s decline, when the railroad changed its projected route to Navasota. After Hempstead was founded in 1857 on the new Houston and Texas Central line, many residents of Rock Island moved there. Rock Island lost its post office to Hempstead in June 1857. Rock Island had been the only sizable population center in the vicinity, but the development of Hempstead brought about its demise. – Source: Handbook of Texas Online
At Rock Island, once a promising village, just a few miles south of Graball, was a fine educational institution, known as the Rock Island Academy, and the youth for many Miles around went there to have their. minds trained. In 1837, legislation having been had providing for the selection of county seats by the vote of the people, Chief Justice John P. Coles ordered an election to be held to locate the county seat of Washington. Rock Island was a candidate against Washington for the honor. At Pecan Grove, the polling place half way between the rival towns, Washington was chosen. When the Houston & Texas Central Railroad wanted to cross the Brazos River at Rock Island. and build into Washington for a bonus of $11,000.00, Washington refused, and this was the death of Rock Island, and the death of Washington also. Rock Island was given its name by Amos Gates. – The History of Washington and Brenham County, 1915, by Mrs. R. E. Pennington.