Named for their bags made from old carpets, these Northerners who moved South during the Reconstruction Era for generally financial purposes were derisively known as carpetbaggers.

Finished in 1825, the Erie Canal runs across New York State, connecting the Atlantic Ocean with the Great Lakes.

Samuel Slater was a British-born industrialist who came to America towards the end of the eighteenth century. He is generally credited with having brought the Industrial Revolution to the United States, in the form of textile factories. 

The steel plow was invented by John Deere in 1837. Deere moved to Illinois and worked as a blacksmith for many years; as the story goes, he was attempting to use a cast-iron plow and found that it was unsuited to the rough soil of Illinois, so he fashioned a steel plow. The importance of the steel plow to the growth of American agriculture, industry, and society would be difficult to overstate. It is generally referred to as the invention that opened up the West. It allowed farmers to work land previously thought untenable and greatly increased individual profits.

The Pacific Railroad Act of 1862 chartered the Union Pacific Railroad Company and the Central Pacific Railroad Company to construct a railroad linking the west with the established eastern railroads.

Shortly after the creation of the new country, New York was expanding but faced a geographical problem. Although blessed with a safe, natural harbor, getting supplies to ships at that harbor was difficult, as the Hudson River connected to no other major watersheds. New York Governor DeWitt Clinton helped remedy this by building a canal from the Hudson River to the Great Lakes, cutting across the length of the state. The canal allowed crops and resources from the Midwest to reach the Eastern seaboard through New York Harbor, and New York City quickly became the nation's largest metropolis.

The cotton gin was invented in 1793 by Eli Whitney. The invention of the cotton gin was important for a number of economic and social reasons. Firstly, it enabled for mechanized removal of seeds from cotton, a process that had previously been extremely labor intensive. This change allowed for rapid growth of cotton plantations throughout the South and the growth of the Southern agricultural system. Secondly, as a result of being extremely profitable, it provided a massive boost to the slave trade. Previous cash crops had been slowly growing less profitable due to the intensity of work required to harvest; however, the cotton gin instantly transformed the production of cotton into a profitable venture. Many historians contend that, without the invention of the cotton gin, the social and economic growth of the South would have been radically different. 

Vertical integration describes the process by which a company seeks to acquire every element of the production chain to keep costs down. The practice was innovated by Carnegie Steel in the 1880s, which not only owned steel mills, but iron ore mines, distribution systems, and sales operations. Vertical integration became a key to the rise of many monopolies during the Gilded Age and remains a favored corporate tactic today.

Cotton was the main source of income for the South during the Civil War. A major reason for Southern resistance to the abolition of slavery (aside from racism) was economic. Unpaid labor supported the Southern States most profitable economic activity.

The 1890 Census declared that frontier was fully settled and no longer existed as it found that there was no longer any clear line of advancing settlement. The Dawes Act, the 1889 Oklahoma land rush, and the surrender of Geronimo were events of the 1880s that each concerned specific areas of the frontier and did not by themselves lead directly to the 1890 declaration that the frontier was fully settled. The Wounded Knee Massacre occurred in December 1890, concerned a small specific area of the frontier, and did not have a major impact on settlement.