In the summer of 1878, bridge viewers determined that a bridge was needed over the Octorara at Mercer's Ford between Sadsbury Township and West Fallowfield Township, Chester County. Lancaster and Chester County commissioners met in Christiana during July 1880 to receive proposals for a wooden inter-county bridge at Musser's Fording, with bids submitted by B. J. Carter, Keogh & MoManns, E. MoMellon, John A. Welmor, E. O. Doets, Darlington & Smith, Ruth & Merritt, and Ruth & Co. Chester County commissioners were to award the contract and superintend construction, while Lancaster County paid half the expense. Officials began staking off the land at Mercer's Ford on August 31, 1880, and B. J. Cárter built the bridge in the following weeks for $1,562.50. During the 1780s, James Sterritt built a mill near the bridge that later became known as Mercer's Mill, and in 1877 Rachel Mercer purchased the adjacent paper mill by sheriff sale, giving the bridge the family name it still bears. The bridge is one of several built between Lancaster and Chester Counties and is notable for unique horizontal wood framing and portal details resembling Greek columns.