My guess would be the first one , 1830 , Hope it’s the correct answer ! :)
The massive land grab was significant because the question of extending slavery into newly acquired territories had turned into a leading political issue
Answer:
Its the first one !!
Explanation:
The Potsdam Conference is perhaps best known for President Truman's July 24, 1945 conversation with Stalin, during which time the President informed the Soviet leader that the United States had successfully detonated the first atomic bomb on July 16, 1945.
France. In the aftermath of the invasion of Poland, Great
Britain and France declared war on Germany. Germany used an excuse that the
Germans in Poland were being persecuted. This invasion was one of the events
that led to World War II.
The westward movement of the American population occurred in intermittent flurries of settlement. The first began early in the nation's history, resulting in the statehood of Vermont, Kentucky, Tennessee, and Ohio, all of which were admitted to the Union between 1791 and 1803. With the Louisiana Purchase the US doubled in size, opening up new regions to exploration and settlement. Once the War of 1812 ended, expansion began in earnest. The government was eager to enlarge the Union, and, accordingly, six new states joined the Union between 1816 and 1821: Indiana, Mississippi, Illinois, Alabama, Maine, and Missouri.