What were the key social, economic, and political changes over time from the 1770s to the 1860s? How did debate about who is an American and...

The big social change between the 1770s and the 1860s in America would have to be the abolition of slavery.  After the Revolutionary War, many Northern states freed their slaves, but the South maintained slavery because it was an economic necessity to operate the plantations.  Slavery was the issue that divided the nation in 1861, leading to the Civil War.  After the war, the key social issue would concern what to do with the newly...

The big social change between the 1770s and the 1860s in America would have to be the abolition of slavery.  After the Revolutionary War, many Northern states freed their slaves, but the South maintained slavery because it was an economic necessity to operate the plantations.  Slavery was the issue that divided the nation in 1861, leading to the Civil War.  After the war, the key social issue would concern what to do with the newly freed slaves and what rights they should have.  

Economically, the nation switched from a collection of small farms and shops to factories and large-scale agriculture.  This transition required large-scale infrastructure investment; this would bring up the issue of who would pay for these improvements.  The Whig Party led by Henry Clay and others created what they called the American System, which relied on federally sponsored infrastructure improvements funded by tariffs and a national bank.  The Democrats, initially under the leadership of Andrew Jackson, saw this as governmental overreach; he broke up the Bank of the United States, thus creating rampant speculation and poor banking practices that would lead to the Panic of 1837.  Economics was also tied to the slavery issue, especially since by 1860 the slaves in the country were worth more than all the railroads and banks combined.

Politically, the issue would be how to balance the power between the states and the federal government.  The Constitution solved this issue by giving the federal government some duties (such as lawmaking and establishing currencies and foreign relations), but the Tenth Amendment protects the rights of states.  The issue of secession came up before the Civil War during the Hartford Convention during the War of 1812 and the Nullification Crisis in which South Carolina, under the leadership of John Calhoun, promised to leave the Union rather than pay a tariff.  In both cases the rest of the nation pressured the potential breakaway states to stay.  By 1861, however, there was enough secessionist sentiment in the South to create a feeling that secession was the only way for the region to maintain its economic livelihood and culture.  

Your paper appears to be quite broad in scope.  If I were you, I would look at how slavery affected the nation economically, socially, and politically during these ninety years.  I think if you do this you can create a strong thesis that would make the paper cohesive.