The Clark Block, located at 401-409 Main Street in Worcester (not to be confused with the Clark Building at 492 Main Street, which does not survive today), was built in 1854 for William Clark to plans by Elbridge Boyden. For many years it remained one of the grandest buildings in the city, housing many institutions and businesses. In the 1850s, the adjacent Richmond and Piper Blocks were constructed. J.H. Walker acquired the Clark Block in 1884 and built an addition on the Mechanics Street side of the building. The Clark Block originally had a facade of thirteen bays along Main Street, but six of these (as well as the adjoining Richmond and Piper Blocks) have been covered over. The first two floors of the remaining bays have also been covered, leaving only part of the original facade visible.