Question

What was one of the most significant changes that happened in the united states in the nineteenth century

Answer 1

here were two technological innovations that profoundly changed daily life in the 19th century. They were both “motive powers”: steam and electricity. According to some, the development and application of steam engines and electricity to various tasks such as transportation and the telegraph, affected human life by increasing and multiplying the mechanical power of human or animal strength or the power of simple tools.

Those who lived through these technological changes, felt them to be much more than technological innovations. To them, these technologies seemed to erase the primeval boundaries of human experience, and to usher in a kind of Millennial era, a New Age, in which humankind had definitively broken its chains and was able, as it became proverbial to say, to “annihilate time and space.” Even the most important inventions of the 19th century that were not simply applications of steam or electrical power, such as the recording technologies of the photograph and the phonograph, contributed to this because they made the past available to the present and the present to the future.
The 1850 song, “Uncle Sam’s Farm,” written by Jesse Hutchinson, Jr., of the Hutchinson Family Singers, captured this sense that a unique historical rupture had occurred as a result of scientific and social progress:

Answer 2

I think it was the Great Depression.