Historically, the site of the Hill-to-Hill Bridge was home to a ferry. The first bridge, a small one lane covered bridge was completed in September 27, 1794. In 1816 an uncovered bridge was built to replace the original and opened for travel on October 19, 1816. In January of 1841, a flood destroyed the structure. That same year a new bridge was built at the cost of $7,258 ($175,000 in 2018) and opened on September 20, 1841. A number of improvements and rebuilds kept the old bridge in use until the early 20th century.
By 1921, Bethlehem’s old covered bridge was in disrepair and disuse after years of fires and floods and made its viability often in doubt. Additionally, the new corporation of the South Bethlehem with Bethlehem facilitated a need to adequately connect the two parts of the city. The newly formed Bethlehem Bridge Commission hired Rodgers & Hagerty Inc. in the summer of 1921 to construct the bridge. Construction began later that year. The new bridge was completed in 1924 and dedicated on November 1st. Originally the bridge had several ramps and branches on either side of the Lehigh, but has undergone several updates and changes in the years since.
Some pertinent facts regarding the construction of the Hill-to-Hill Bridge:
Total approximate cost: $3,000,000 ($44,000,000 in 2018)
Type: Spandrel, with Reinforced Concrete Arches.
Height of bridge roadway from average water level: 48 feet
Deepest pier sunk: 51 feet below ground level
Longest concrete arch span: 146 lineal feet
Number of arch spans in bridge: 26
Carloads of materials: 216 Lumber, 1940 Sand, 314 Stone.
Concrete was provided by the Pennsylvania Cement Company (Bath location), Steel reinforcement by Bethlehem Steel, Sand by Morris Black of Bethlehem, PA, and castings by Bethlehem Foundry and Machine Company.
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Source: Keim, Rollin Reuben. The Hill-to-Hill bridge, Bethlehem, Pa. : Including Historical Review and Engineering Features. 1924.