The Brazoria County Historical Museum is housed in the 1897 Brazoria County Courthouse. In the late 1970s, the courthouse was slated for destruction. With widespread community support, the Brazoria County Historical Commission petitioned the Commissioners Court to save the structure and utilize it as a museum. On March 26, 1979, County Judge E.E. Brewer signed an agreement with the Commission, leasing the courthouse to the Commission for 100 years. Its terms required the Commission to renovate the facility without county funding and open it to the public within two years. The lease was later assigned to the Brazoria County Historical Museum, Inc., a not-for profit corporation. The move was made to improve the museum's fund-raising capabilities. Beginning with a $22,000 grant from DOW Chemical and donations from county residents, restoration efforts began in earnest. Also in 1979, the entire Courthouse Block was placed on the National Register of Historic Places.

In 1980, the Historical Commission sub-leased the building's lower east wing back to the County to house the Adult Probation Department. In return, the County weatherproofed the structure, installed heating/air conditioning on the first floor, rewired the lower floor, and installed first floor restrooms for the public.

Renovation funding continued at a fast pace to meet the lease requirement that the building open in 1981. A $10,000 grant from the Texas Historical Commission offset roof repair costs. The Moody Foundation awarded an additional $15,000 for repairs. As scheduled, the Commission held the preview opening March 29, 1981.

In 1982, the Museum hired its first permanent staff member, Ted Hollingsworth who, with the assistance of a large cadre of volunteers, began designing and installing the downstairs exhibit area. Renovation work continued. Taysom Roofing received the roof repair contract and the Texas Historical Commission granted additional funding to repair and/or replace the building's doors and windows.

In January, the County Historical Commission voted to establish a separate Museum Board of Trustees. The board included seven Commission members and seven members-at-large. County financial support for the museum began in 1982, when the Commissioners' Court allocated $35,000 in operating funds for the 1983 fiscal year.

The next major phase in the Museum's development was the hiring of Renovation Architect Graham B. Luhn who designed the renovation master plan. These plans remain the basis for ongoing restoration projects throughout the facility.

The Historical Commission could not have accomplished the extensive renovations without financial support from Brazoria Countians. The Museum organization was very fortunate to have the late Jim Nabors, editor of the Brazosport Facts, on its fundraising team. As the 1982 fundraising chair, he raised $230,000, exceeding the original goal by $80,000. They employed many unique fundraising techniques including the symbolic purchasing of the 23rd District Courtroom windows for $10,000 each. The Brazosport Rotary donated $40,000 for renovations to the curator's office and workroom. Mrs. Lois Adriance provided baseline funding for the development of the Adriance Research Library.

In 1987, contractors renovated the 23rd Judicial District courtroom. They replaced the deteriorated wood floors and repaired the plaster walls. The Museum held a rededication dinner ceremony in the renovated courtroom on September 9, 1987, with T.R. Fehrenbach attending as the honored guest.

After the Adult Probation Department vacated the lower east wing in 1989, it was converted into an auditorium and offices. The west wing offices became additional exhibit space and the Windows Book and Gift Shoppe.

While continuing with facility upgrades, the Museum Board began developing the permanent Austin Colony exhibit, to be housed in the former courtroom. Chairperson Beth Griggs and the exhibit committee worked for more than five years to develop the exhibit theme and design, locate funding, and install the $150,000 exhibit. The Austin Colony exhibit give patrons a definitive interpretation of the events leading from the earliest inhabitants, to the Anglo-American immigration into Spanish Texas, and through and including the Texas Revolution and Independence from Mexico. It introduces visitors to Anglo-Texas life and culture where it began and focuses on the Colony's development and history in what in now Brazoria County.

Since its 1993 opening on the eve of Stephen F. Austin's 200th birthday, the exhibit has received many awards of excellence. In 1994, it received the American Association of State and Local History's Certificate of Commendation. This award is presented for excellence within the context of available means and regional standards. That same year the Texas Historical Commission selected the exhibit for its annual Award of Excellence.

Within three years of its opening, the Austin Colony exhibit went online at the Museum's Colonial Texas Website. The Website includes the complete exhibit, the " Old 300" genealogy database, an index to the museum's artifact and document collection, and an index of the Adriance Research Library's 4000 image historic photo collection. It also privides links to other Worldwide Web history information resources.

The Museum's Website has garnered yet another national award--the American Association of State and Local History's 1997 Award of Merit. The award is presented to the museum whose performance AASLH deems excellent compared with similar activities in North America.