The Hill Valley Civic Committee was an organization in Hill Valley. In an alternate timeline where an elderly Biff Tannen from 2015 gave his younger self from 1955 a sports almanac to make himself rich, it became a secret organization to protest BiffCo, which Biff was using to construct properties that suited his own interests.
On March 16, 1973, George McFly was to be presented a book award by the Hill Valley Civic Committee. In the alternate timeline, George never made it to the ceremony because he was shot and killed by Biff Tannen in an alleyway. Later that year, Lorraine Baines McFly was forced to marry Biff to help her family, who were in trouble due to Biff's actions.
In 1973, in the alternate timeline, the Hill Valley Civic Committee consisted of George McFly, Goldie Wilson, Stanford S. Strickland, Mrs. Blumberg (the editor of the Hill Valley Telegraph), Mark Dixon, Terry, and two other individuals. George McFly was the head of the Hill Valley Civic Committee before his death.
In 1983, Goldie Wilson was the head of the committee, and they got a new member, Dave McFly. Dave revealed that his stepfather, Biff, kept a safe in his office. Dave turned off the security alarms to allow Terry to enter to break into the safe. However, Biff witnessed the attempt to break into the safe, and had the Hill Valley Police Department, which he controlled, beat him to death. Biff then had them kidnap Dave, and since he promised Lorraine he wouldn't hurt her children, he had them tell Dave to leave Hill Valley and never return.
At that point, things looked bleak. However, Dr. Emmett Brown revealed that he was their silent benefactor. He let them know that he had let the rumors that surrounded him since his time on the Manhattan Project continue so that he could work on his project in peace, even from BiffCo. He revealed to them that the project that he was in the process of constructing was a time machine.