its beginnings, the United States has spread westward
and acquired territory. At first this meant dealing with
European colonial competitors such as France and Spain,
as well as native groups that already claimed the land.
Eventually, the idea that the United States should
occupy all of the land between the Atlantic and Pacific
Oceans, that it was our manifest destiny, became
In 1803, President Thomas Jefferson doubled
the size of the United States by purchasing the
Louisiana Territory from the French. This purchase
troubled Jefferson somewhat because he used his
presidential treaty-making powers to craft the
agreement. He considered this to be a loose
interpretation of these powers, and he believed that
the Constitution should be interpreted strictly.
In 1820, the first of several debates over the expansion
of both the United States and the institution of slavery
took place. Missouri wished to enter the union as a
slave state, however, this would grant slave-holding
states the majority in the Senate. This arrangement was
unacceptable to the industrial North, which did not
depend upon slavery as the South did.
Congress passed the Missouri Compromise which would
allow Missouri to enter as a slave-holding state and
Maine as a free state. This act also banned slavery in
the Louisiana Territory north of the 36 degree 30 minute
line of latitude which was the southern border of
The California gold rush in the late 1840s and
the acquisition of new territory of Utah and New
Mexico after the Mexican-American War required
Congress to analyze the intertwined issues of
expansion and slavery again since the Missouri
Compromise only applied to the Louisiana Territory.
This time, Congress allowed California to be admitted
as a free state and southerners were granted a stricter fugitive
slave law allowing them to recapture their property,
even in the North. Finally, popular sovereignty
would allow the people living in the Utah and New Mexico
territories to vote on the issue of slavery when they
entered the union as states.
In 1854, Congress decided to extend popular
sovereignty to the unsettled areas of the Louisiana
Purchase, now know as the Kansas and Nebraska
territories. This act led to violence and a pre-cursor
to the Civil War as pro-abolition and pro-slavery
forces flooded Kansas to sway the vote, in what became
known as Bloody Kansas.
The United States also went on to acquire
Alaska and Hawaii which also became states. Imperialism
also resulted in the possession or control of Cuba, Puerto
Rico, the Philippine Islands, and the Panama Canal.