Delaware - General information.   Delaware never had very many covered bridges, and the few historic covered bridges the state had were all located in the northernmost county of New Castle.  In 1937, there were over thirty five covered bridges, but by 1954, these historic structures numbered only four; today, only two remain, and these two still carry motor traffic. Of the six covered bridges in Delaware today, two are authentic historic covered bridges, and four are non authentic modern covered bridges.  Four covered bridges are located in New Castle County, and one each in Kent and Sussex Counties.  Ironically, the historic bridges are of similar age, built in 1870 and the modern bridges were built between 1960 and 1987.  Both of the two remaining authentic bridges have Town lattice truss supports.  Fortunately, Delaware is maintaining their two historic covered bridges.  The earliest record of a covered bridge in Delaware is of one built over the Brandywine  “Near Wilmington” in 1820-21.  It may have been the single span arch erected near the present Augustine cut off a short distance northwest of the city.  Another was the old Market Street Covered Bridge in the center of Wilmington.  It was a double-barreled bridge with encased arches, false front portals and twin side walks, and a Wilmington Landmark until 1889.  In Rising Sun there was a Powder Keg Mill and cluster of workers’ homes with another twin lane span high above the Brandywine.  This bridge, built in 1833, had a useful life of well over eighty years.  Further upstream were Rockland and Thompson’s Bridges, which survived until recent years.  The most unusual of Delaware's covered bridges was the one that crossed the famed Deep Cut on the Cheasapeake and Delaware Canal.  Twenty-five hundred men dug and blasted through a ridge of solid rock nearly a mile long to create this gash.  Even before the canal was completed, the cut was spanned in 1825 by a graceful wooden arch some 90 feet above the water.  This covered bridge, with its ornate windows and boxed portals, became a landmark to helmsmen guiding their canal boats behind plodding mules along the old waterway.  Known as both Buck’s Bridge and Summit Bridge, the high span was replaced in 1872 by a swing draw bridge at a lower level.  Northeast of Granogue, and only a few paces from the Arc of the Northern Boundary, is Smith’s Bridge, the best preserved  of Delaware's remaining authentic covered bridges.  Built in 1839 at a cost of $5,446.00, this 154 foot bridge with its concentric arches carries a good deal of traffic across Brandywine Creek.  The structure was completely rebuilt in 2002.