In your opinion, what is the most important/significant event in 19th century American history?

Question

In your opinion, what is the most important/significant event in 19th century American history?

Answer 1

The Civil War and the Industrial Revolution

Answer 2

This one is a no-brainer:  The establishment of the Church of Jesus Christ of Latter-day Saints in 1830.  This single act will have a greater impact on the world than any other act in any country during the 19th Century.

Answer 3

The civil war, you know; freeing the slaves because not only were the slaves freed, but the abolitionists could stop arguing with the southerners, and people could finally move off the 'oh free the slaves-oh no they needn't be freed' argument and actually start  developing infrastructure, machines, schools..you get what i mean, they finally moved on......and became a great country.