Bridge building was primarily a local affair well into the twentieth century, with the county governments playing the dominant role. Beginning in the nineteenth century, Pennsylvania law allowed county commissioners to take responsibility for bridges only after local residents had petitioned the county court and secured the concurrence of court-appointed viewers and a grand jury. A provision passed in 1879 gave the county commissioners the option to furnish money to a township to build bridges without the county incurring future liability for maintenance, repair, or rebuilding. These laws made the county government the key player in bridge construction until the 1920s, when the Pennsylvania State Highway Department (PennDOT’s predecessor) took over most of the responsibility.

       By the late nineteenth century, when truss bridges began to be built in great number, the bridge building process had become formulaic, because it was steeped in a routine developed over a 100-year period.  The process generally began with local landowners petitioning the county Court of Quarter Sessions for a new or replacement structure. The petitions invariably stated that a bridge was "much needed" at a location, that the expense of constructing such a bridge was too great for the township to bear, and that the county government should therefore build and maintain the structure.

       In response, the Court would appoint three viewers to inspect the proposed crossing and report on whether a bridge was warranted at that location. The petition and viewers' report would then be presented to a Grand Jury, which would recommend whether a bridge was necessary. If the Grand Jury found that it was, the findings would next be conveyed to the County Commissioners, who would vote whether to accept the bridge as a county bridge. If they did, the commissioners would then have specifications or formal design drawings prepared and advertise for construction bids.  Bridge fabrication companies would respond, presenting designs and prices; the low bidder was generally awarded the contract. Once the bridge was erected, the Commissioners would appoint inspectors to insure that the bridge was built according to the specifications.

The County Engineer

       By the first decade of the twentieth century, most counties employed a County Engineer, either as a salaried employee or as a contractor. The County Engineer drew up bridge plans and the specifications used in the bidding process. He met with representatives of bridge fabricating companies at the proposed bridge location to discuss site factors and bridge design ideas. He reviewed incoming bids for technical correctness and appropriateness. Consequently, the County Engineer held great sway over both the final design of the bridge and the fabrication company chosen to build it.  During the first quarter of the twentieth century, Mercer County Engineers included Lewis Burnside, Frank Graham, and John Harris.

Pennsylvania State Highway Department

       The Pennsylvania State Highway Department became the key player in highway bridge construction during the 1920s and 1930s.  The State Highway Department was created in 1903 to provide state road aid to second class townships.  (No state aid was available to counties, cities, boroughs, or first class townships.) The State Highway Department's mandate changed following the passage of the Sproul Act of 1911, which created and gave the State Highway Department control over an 8,500-mile state highway system.  Passage of the landmark Federal-Aid Road Act in 1916 made federal funds available to construct bridges under the supervision of State Highway Department officials. The passage of the act, combined with increased state funding allocations and directed tax revenues, marked the beginning of a shift in bridge construction from county to state responsibility.  During the 1920s, for example, the State Highway Department designed more than 1,400 new bridges for Pennsylvania’s roadways.  For longer spans, the Department preferred riveted through truss spans. However, existing county-owned bridges on the state highways remained the responsibilities of the counties until 1929.