The American businesses have been favoring the overseas expansion of the USA because it was in their interest to make more profit.
The overseas expansion of USA meant that bigger market was going to open for the products and goods for the American businesses. Also, they were going to be able to create affiliations in those new territories, which was very desirable because the labor force was much more cheaper but had pretty much the same efficiency.
Also, apart from the opening of the new markets in the gained territories, the businesses, through their affiliations were going to be much closer to the other big markets, thus minimizing the coast for transportation. All of these things were going to make much bigger profit tot he American businesses, so they were very fond of such a move.
The term "Roaring '20s" refers to the decade of the 1920s in the United States, which was a time of much economic growth, as well as much social and cultural change.
In the 1920s, cities grew rapidly and industry was growing immensely in the United States. Jazz and other forms of entertainiment (like radio) were expanding and reaching new audiences. Women were becoming more involved in public life. The stock market was a place of much speculation and investment -- too much, as it turned out. The stock market crashed in 1929. America had thought it was in great times during the Roaring '20s. But then everything came crashing down and minds and hearts were depressed, as the country entered into the next decade and an economic tragedy known as the Great Depression.
You cannot. These states are high in population which has a major impact on the presidential votes. If one does not win over said states, they will mostly lose the election.