The best describes the contributions of frederick douglass during the civil war is : douglass was an abolitionist who encouraged the union to allow african american to enlist
Before his effort, the contribution of African American for the army was limited in the factory, when they labored to create military supply.
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Gravitational force is the force that keeps astronauts in orbit around the Earth and Earth in orbit around the Sun.
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Answer:
Transportation, Communication, Labor
Explanation:
The industrial revolution coincided not only with the beginning of the mass use of machines, but also with a change in the whole structure of society. It was accompanied by a sharp increase in labor productivity, rapid urbanization, the beginning of rapid economic growth, and an increase in the living standard of the population.
Of great importance was the emergence of railways. The first steam locomotive was built in 1804 by Richard Trevitick. In 1807, Robert Fulton built the world's first Clermont steamer, which cruised the Hudson River from New York to Albany. In 1819, the American steamer Savannah crossed the Atlantic Ocean for the first time.
The first electric telegraph was created by Russian scientist Pavel L. Schilling in 1832. Subsequently, the electromagnetic telegraph was built in Germany by Karl Gauss and Wilhelm Weber (1833), in the UK by Cook and Wheatstone (1837), and in the United States the electromagnetic telegraph was patented by S. Morse in 1837. Morse's great merit was the invention of the telegraph code, where the letters of the alphabet were represented by a combination of short and long signals - “dots” and “dashes” (Morse code). The commercial operation of the electric telegraph was first launched in London in 1837. In 1858, a transatlantic telegraph connection was established. Then a cable was laid to Africa, which made it possible to establish a direct telegraph connection between London and Bombay in 1870.
