USA

The Fink Deck Truss Bridge is thought to have been originally used on the Norfolk and Western mainline railway. It was moved to its present location and converted to a vehicular bridge over a railroad spur in 1893 when the Norfolk and Western mainline was moved. It was relocated again in 1985 to Lynchburg's Riverside Park to serve as a pedestrian bridge.

At a time when steam power was finding its first uses in America, Philadelphia opened two steam pumping stations, January 1801, to lift water from the Schuylkill River and distribute it through the city's wooden pipes and mains. By 1811 a new water power works was begun on the river near Morris Hill, and the Fairmount Water Works opened September 7, 1815. These water works represented the first large-scale application of steam pumping to water service in the country.

In its day, the famous Erie Canal was the world's longest canal and America's greatest engineering feat. It was the principal route for emigrants from the East and agricultural products from the West. Before construction of the canal, New York City was the nation's fifth largest seaport, behind Boston, Baltimore, Philadelphia and New Orleans. Within 15 years of its opening, New York was the busiest port in America, moving tonnages greater than Boston, Baltimore and New Orleans combined.  

The stone was set by the joint U.S.-Spanish survey party on April 10, 1799.  Made of sandstone, it is roughly two feet high and eight inches thick. On the north side of the stone is the inscription "U.S. Lat. 31, 1799." On the south side is "Dominio de S.M. Carlos IV, Lat. 31, 1799."

The Wheeling Suspension Bridge was the first bridge to span the Ohio River. It was initially completed in 1849, but destroyed by a tornado five years later. The bridge was rebuilt in 1856. The replacement bridge has the same general appearance of the original structure; the massive towers, anchorage housings, and island approach are all the original stone masonry.

One of the first major efforts to increase farming and encourage habitation in the arid regions of the western United States, the Rio Grande Project was designed to provide reliable irrigation as well as resolve a dispute over water supply with the Republic of Mexico.  The project's centerpiece is Elephant Butte Dam, a concrete gravity structure 301 feet high and 1,674 feet wide. Elephant Butte Reservoir - with a surface area of 36,600 acres and a capacity of more than 2.2 million acre-feet - was the largest reservoir in the world at the time of its completion.

Established in 1935 as the Valparaiso Bombing and Gunnery Base, the base supported the U.S. Army Air Corps, the predecessor to the U.S. Air Force, as its primary facility for training new pilots in bombing and gunnery tactics. It also served as a test facility for aircraft, aircraft armament, air-delivered munitions and other aircraft systems. The base was renamed Eglin Field in 1937 in honor of Air Corps aviator Lt. Col. Frederick I. Eglin, who trained pilots during World War I, and who had recently died in an aircraft accident. After Congress created the U.S.