What were the provisions of the Compromise of 1850? Why was it difficult to get this piece of legislation passed through Congress? What provision...

There were five parts to the Compromise of 1850. First,
California would be admitted to the Union as a free state. Next, two new territories
would be established, Utah and New Mexico, and slavery in those territories would be
determined by popular sovereignty, that is, the people of the territories would decide
the issue. The border of the state of Texas was determined, with Texas giving up some of
its land in exchange for $10 million.  The slave trade, but not slavery itself, was
ended in the District of Columbia.  Finally, a new, strict fugitive slave law was
enacted.  This compromise was difficult to get passed because each part of the
compromise upset one part of the country.  California as a free state upset the south. 
Opening slavery to new territories upset the north. Ending the slave trade in D.C. upset
the south. Passing a new fugitive slave law upset the
north.

The Compromise of 1850 dealt with the land the U.S.
acquired from Mexico in the Mexican-American War.  This land was known as the Mexican
Cession.  The Missouri Compromise of 1820 dealt with the Louisiana Purchase. One part of
the Missouri Compromise said that there would be no slavery in the Louisiana Purchase
north of 36 degrees, 30 minutes of north latitude. In 1854, the Kansas Nebraska Act was
passed. Two new territories, Kansas and Nebraska, would be established in what was the
Louisiana Purchase. These territories were north of 36 degrees of latitude and according
to the Missouri Compromise there would be no slavery there.  But the Kansas Nebraska Act
stated that the issue of slavery in the new territories would be decided by popular
sovereignty, an idea borrowed from the Compromise of 1850.  It was this issue of slavery
in Kansas that led to violence and the nickname given to Kansas at the time—“Bleeding
Kansas”.