Ending the American Revolution and establishing the United States as a sovereign nation comes through a peace agreement that settles the fighting and recognizes independence. The correct choice refers to the Treaty of Paris signed in 1783, which the United States and Great Britain concluded to end the war and formally acknowledge the new nation. Beyond declaring independence, it set boundaries for the United States, roughly from the Atlantic eastward to the Mississippi River and from the Canadian north to Florida in the south, and it addressed issues like fishing rights and the handling of debts and loyalist claims. This moment sits between the Declaration of Independence in 1776, which announced the separation, and the later drafting and adoption of the Constitution in the late 1780s. So, 1783 is the year the war ended and independence was officially recognized.

The main idea is that infrastructure like the transcontinental railroad reshaped the economy by linking distant regions into one large market. By connecting East and West, goods could be moved quickly and more cheaply across the country. This lowered shipping costs and opened up new opportunities for manufacturers, farmers, and merchants to sell across a national audience, not just locally. Firms could plan production around a wider customer base, leading to more investment, growth, and the development of nationwide supply chains. That combination—broader access to markets and cheaper distribution—best describes the railroad’s impact on business in the late 19th century. The other options don’t fit because the railroad actually expanded markets, lowered costs, and facilitated better information flow rather than reducing access, increasing costs, or shrinking markets.

The Tennessee Valley Authority is a federally owned corporation created during the New Deal to bring electricity, flood control, and economic development to the Tennessee Valley. Because it is government-owned and runs a large, integrated system of generation and transmission across multiple states, it has grown into the largest public power company in the United States, delivering electricity to millions of customers. The other options aren’t power providers: one is not a real current entity, another is a regulatory agency that oversaw electricity rather than producing it, and the last was a New Deal program focused on public works rather than operating a utility.

Drafted in secret by delegates to the Constitutional Convention and establishing the government of the United States refers to the Constitution. At the Philadelphia convention in 1787, discussions were held privately to craft a new framework for the nation. The resulting document laid out a national government with three branches, created checks and balances, and established how power would be shared between the national and state governments. The secret sessions were meant to protect deliberations and allow frank debate, and the Constitution replaced the Articles of Confederation, becoming the supreme law after ratification. The other items played different roles: the Federalist Papers were essays arguing for ratification, not a fram­ing of the government; the Lee Resolution declared independence, and the Treaty of Paris ended the war and recognized independence.

The main idea here is how the Compromise of 1850 handled the issue of slavery in new territories: it let the people living in those territories decide through popular sovereignty whether slavery would be legal there once they apply for statehood. This meant that residents in Utah and New Mexico would vote to determine if slavery would be allowed, rather than having Congress impose a blanket rule. It was a negotiated balance between free and slave state interests, aiming to reduce conflict by deferring the decision to local voters. This matches the option describing popular sovereignty for admitting new states. The other provisions—making California a free state, banning the slave trade in the District of Columbia, and settling Texas boundaries—address different parts of the compromise and do not describe how slavery would be decided in new states.