Many early truss bridges were built of wood; one that was erected across the Susquehanna River in Pennsylvania in 1815 had a span of 110 meters.

• 许多早期的桁架都是用木料修建的。1819年在宾夕法尼亚州的少斯昆哈拉河上修建的木桁架桥跨度为110米。