Nikola Tesla was a Serbian-American inventor, electrical engineer, mechanical engineer, physicist, and futurist who is best known for his contributions to the design of the modern alternating current electricity supply system. Born and raised in the Austrian Empire, Tesla received an advanced education in engineering and physics in the 1870s and gained practical experience in the early 1880s working in telephony and at Continental Edison in the new electric power industry. He emigrated to the United States in 1884, where he would become a naturalized citizen. He worked for a short time at the Edison Machine Works in New York City before he struck out on his own. With the help of partners to finance and market his ideas, Tesla set up laboratories and companies in New York to develop a range of electrical and mechanical devices. His alternating current (AC) induction motor and related polyphase AC patents, licensed by Westinghouse Electric in 1888, earned him a considerable amount of money and became the cornerstone of the polyphase system which that company would eventually market. Attempting to develop inventions he could patent and market, Tesla conducted a range of experiments with mechanical oscillators/generators, electrical discharge tubes, and early X-ray imaging. He also built a wireless-controlled boat, one of the first ever exhibited. Tesla became well known as an inventor and would demonstrate his achievements to celebrities and wealthy patrons at his lab, and was noted for his showmanship at public lectures.

John Rennie was a Scottish civil engineer who designed many bridges, canals, and docks.

John Augustus Roebling was a German-born American civil engineer. He designed and built wire rope suspension bridges, in particular the Brooklyn Bridge, which has been designated as a National Historic Landmark and a National Historic Civil Engineering Landmark. On May 22, 1831, Roebling left Prussia with his brother Carl and Johann Adolphus Etzler, who believed in a technological utopia, and a group of emigrants. Engineers had difficulty advancing and achieving economic mobility in Prussian society. The Napoleonic Wars, which lasted until 1815, had suppressed investment in infrastructure. During this period, Prussia had political unrest, as authoritarian governments took the places of democratic ones. Etzler had ideas about creating a utopia in the United States, but disputes arose en route, and the group split up. John and Carl purchased 1582 acres (6.4 km²) of land on October 28, 1831, in Butler County, Pennsylvania with the intent to establish a German settlement, to be called Saxonburg. Most of the other settlers had remained with Etzler. The John Roebling House at Saxonburg was listed on the National Register of Historic Places in 1976. When the Roeblings and others arrived, the United States was in the later stages of an economic boom, which ended in the Panic of 1837. Farmers were deeply affected by it. By the 1840s, many Americans believed in the nation's manifest destiny to extend its borders and achieve greatness. Transportation between eastern industrial hubs and frontier farming markets had become a matter of both national and popular interest. Many railway and transportation projects were underway near the site which Roebling chose for his colony, but instead of continuing in the engineering profession, he took up farming. After five years he married Johanna Herting, a tailor's daughter.