To what extent was late nineteenth-century and early twentieth-century United States expansionism a continuation of past United States expansionism and to what extent was it a departure? The United States steadily grew from the beginning of its history and it needed more land to support the growing number people that were living on the continent. At first, the Americans felt that they had the God-given right to expand all the way to the Pacific on the North American continent, but when all the land had been taken, they decided that it was time to expand elsewhere in the world. Expansionism has always been in the United States' history and will always continue if the United States wants to continue to be a world power. The reasons for early and later expansionism in the United States were more or less the same, while the processes the United States went through to expand and the areas it expanded into were different in the later expansionist era of the United States. When the United States started running out of space for the people to live during the first era of expansion, they used manifest destiny to justify their expansionist goals to the Pacific. They needed new markets for their goods and more land for farming.

The influx of people into the country also added more pressure to the people to expand. The growing population put a lot of stress on the country's natural resources and they felt the needed to find alternate resources. The Americans also felt the need to spread what they felt were superior institutions to the people that they felt were inferior. Racist reasons were prevalent in both early and later expansionist eras. Americans felt it was their duty to "help out" these unfortunate peoples and institute the American institutions as a model society to them.

In the later expansionist era, Americans felt that it was also their duty to enter other countries and help them if the Americans felt that the other countries weren't stable enough to rule on their own. Cuba was an example where the United States went in and took over when rebellions were occurring against the established government. The reasons for expanding throughout the world and across the continent were more or less the same during both eras of expansion. In the early expansionist era, the United States was expanding to relatively unsettled areas with sparse Indian populations, while in the later era; they were going into established countries and trying to gain influence there. By the second expansionist era, the United States had already had a lot of experience in subjugating the people of their own continent.

When they first expanded, the Americans imposed their own institutions upon the Indian tribes that populated much of the western areas of the continent. If the Indians wouldn't comply with the Americans' wishes, they were simply forced out by armed soldiers. When the Americans once again started to expand later, they went into other countries to try to help the people there that had an unstable government. The Roosevelt Corollary was added to the Monroe Doctrine, which said that the United States could intervene in any country where they didn't have the ability to rule themselves with a stable atmosphere. When the Americans first expanded, they were subjugating people and in the later expansionist time, the Americans said that they were "helping" the other countries, when in truth, their goal was still the same. They wanted to extend their influence worldwide.

When the Americans first expanded, they were using the belief in Manifest Destiny to justify their expansion across their own continent. This was the feeling that the Americans had the right to expand from coast to coast on the North American continent and nothing should be done to stop them. Later on, ideas such as the closing of the frontier caused Americans to start looking overseas for more land. They were afraid that the natural resources on the North American continent would soon run out and they had to find alternate sources overseas.

Americans went into other countries to extend their influence. They even went as far as China hoping to get some land just like the other European countries were doing. The Americans hoped to gain foreign markets, while extending their influence to other areas. Dollar Diplomacy was one of the ways the Americans tried to extend economic influence to other countries. Expansion was now going to all parts of the world, while it was contained in just the North American continent in the past.

Expansion is an important part of all countries. It is the way for the countries to become more powerful and this was what the United States tried to do in the past. When they felt that they had used up most of the land on the North American continent, they shifted their expansionist goals overseas. The reasons stayed the same throughout both expansionist eras because all countries more or less expanded for the same reasons. Power is an important part in a country's existence and each country strived to gain more and more of it in the past.