The period after the Civil War was an important period in terms of technological innovation in the United States. The telegraph existed before the Civil War, but it proved invaluable in moving men and supplies during the war. After the war, the telegraph found more commercial uses and, combined with an ever-expanding rail system, helped to link the United States commercially. The telegraph also allowed for the spreading of the news industry in the United States, as newspapers could learn of events in a matter of minutes in order to print both morning and evening editions.

Mass production in terms of food and clothing was also a technological innovation that was spurred on by the war. By the end of the war, the Union army had over one million men in uniform. One of the greatest feats of the war was feeding and clothing all of these people efficiently. The end of the war saw mass-produced clothing techniques being applied to the commercial sector. Department stores soon used clothing lines produced by cheap immigrant labor to sell clothes to a large audience. Though the rich continued to use tailors, mass-produced clothing would become a department store staple for years to come. Canned meat and fruit was also common in general stores and eventually in supermarkets. Companies such as Armour became famous worldwide for meatpacking.

Like many other wars, the Civil War caused military research that led to inventions that were aimed to tip the scale of battles. The period after saw veterans coming back to work on many related projects.

The Transcontinental Railroad was completed in 1869. The two coasts of the United States were now linked by rail through the middle. The ease of travel from the ports of the east coast to the vast open space of the midwest and west led to a huge boom in population. The improved railroad networks which grew in the post-war period allowed the economy of the United States to strengthen. Raw material and foodstuffs flowed from country to cities and fueled urban growth. Westward expansion from the eased travel sprawled the growth out from the east coast and across the entire country.

In 1879, Thomas Edison discovered electricity. This was one of the biggest discoveries of the modern world. Electricity was a huge upgrade from the dangerous and expensive alternatives such as kerosene that were in use before it. Power could now be used at previously unthinkable levels and allowed for innovation across industries.

To help the wounded from the war, prosthetics were improved significantly. For the first time on a large scale, amputees were given more realistic prosthetics than simple hooks of peg legs. Improvements on hinges for limbs and cosmetics to give a more life like appearance gave wounded veterans a luxury new to the world. Prosthetics would also be universally adopted and continuously improved thanks to the benefits they demonstrated with Civil War veterans.

The most important technological advances were those that were related to railroads and perhaps agriculture.  These were the advances that made the industrialization of the post-Civil War period possible.

Agriculturally, there were inventions like James Oliver's chilled-iron "sodbuster" plow which was able to cultivate the Great Plains and open up a new "breadbasket" for the US.  Other inventions and advances were made in things like threshing machines that allowed faster harvest of grain.

Closely related to these advances were advances in railroad-related technologies.  These advances allowed railroads to spread across the country, bringing things like the agricultural products from the Great Plains back to urban centers.  These included things like the Bessemer Process that made cheaper steel for better rails, the refrigerator car for trains, and improvements on telegraph systems.

All of these advances allowed railroads to become the "first big business" and the most important industry of the post-Civil War era.