George Wetmore Colles, Jr. (1871–1951), an electrical and mechanical engineer educated at Yale University (BA 1892) and the Stevens Institute of Technology, bought property in the area around 1900 and called his estate the Rose of Sharon Garden Ranch after the many Cherokee Roses (Rosa laevigata) that grew there.

A new post office was dedicated under President Ronald Reagan and operates today.

Students began being bussed to Angleton in the late 1900s, a practice that continues to this day.

[15] In 1985 Yani Rose Keo, a Cambodian American, established a farm in an area called "Little Cambodia",[18] in Brazoria County, near Rosharon.

Terrence McCoy of the Houston Press stated that there were "perhaps" 90 families of Cambodian origin living there.

[18] As of 2015[update], 77583, the ZIP code of Rosharon, Texas, has the highest concentration of Cambodian Americans in the Greater Houston area.

[24] The Handbook of Texas stated that the prison authority employees and their family members "added considerably to [Rosharon's] economy.

In the 1940s Rosharon community members, wanting to start a fire department, met with Brazoria County officials and purchased firefighting equipment.

From the 1940s until 2004 the firefighting department received all of its support from fundraising events, private donations, and small contributions from the Brazoria County government.

[26] The United States Postal Service operates the Rosharon Post Office at 1810 East Farm to Market Road 1462.

Almeta Crawford High School of FBISD has a Rosharon postal address, but is not in the CDP.

Almeta Crawford is an African- American teacher who worked for the Fort Bend School district for 27 years.