The town of Hill Valley was first settled in 1850 and was incorporated in 1865. By the 1880s, it was connected by railroad to its reality's San Francisco. Construction of a new county courthouse was well underway in 1885, the year a new clock was dedicated for the building. The Shonash Ravine Bridge was completed in the Summer of 1886, around the same time the ravine was renamed the Eastwood Ravine Bridge. (In one timeline it had been called the Clayton Ravine Bridge, when Clara Clayton had fallen into it due to a spooked horse. Thanks to the temporal incursion of Marty McFly and Emmett Brown, this did not com to pass).
The area near the courthouse was developed into a downtown area which became known as the Hill Valley Town Square. Several shops and businesses opened up in the vicinity of the courthouse. On Saturday, November 12 1955, at 10:04 p.m. PST, lightning struck the courthouse's clock tower, freezing the clock at 10:04. The clock was never repaired and as it became a landmark of Hill Valley over the years, it was preserved in its non-functional state by the Hill Valley Preservation Society.
By the 1980s, Hill Valley Town Square was experiencing a recession, several businesses and shops had closed down or moved. The reason: A large shopping mall, the Twin Pines Shopping Mall, opened up near the outskirts of town and took away much of the business of the area.
However, during the 21st Century, the town square experienced a revitalization. Many new shops opened up near the courthouse and the courthouse was turned into the Courthouse Mall. Businesses began to move back into and around the town square and the parking lot was converted into a pond. The clock on top of the courthouse was still preserved at 10:04 due to the continuous efforts of the Hill Valley Preservation Society. (Back to the Future Trilogy)