Conclusion

Modern engineering transformed American life in three broad periods. In the first, from the nation's independence until after the Civil War, engineers created new industries of iron and textiles, communication by telegraph, and new transport by steamboat and then railway. In the second period, from the 1870s to the 1930s, engineers changed America from a mostly rural and agrarian society to a mainly urban and industrial one, through new engineering led by telephony, steel and chemicals, motor vehicles and aircraft, radio, electric power distribution, and the use of new materials, steel and concrete, in building. The third period overlapped the second in the 1920s and 1930s, as engineers began to control great rivers for water and power and began to interconnect the nation with paved highways. Express highways and taller buildings came in the 1950s and 1960s. After 1945, nuclear energy introduced a new if controversial source of power, jet engines remade air travel, and rockets reached into outer space. A revolution in electronics and computing began that is still unfolding today.