"Our manifest destiny is to extend the continent allotted by Providence for the free development of our annually multiplying millions."- John L. O' Sullivan, 1845. In 1820, the American population numbered 9,638,453 citizens, as well as owning 1,749,462 square miles of land. Due to the population continuing to grow, America must find a way to expand more land for more people to live on, creating the birth of the expansion of the Western world. From just nine million people, America has grown dramatically to 23 million citizens in just thirty years. As he explores more and more lands, including newcomers. In this essay I will show how America developed and grew due to this event, and how it began, what kind of events happened, how America is America today. To begin with, the idea of ​​​​the expansion of the Western world was started by a group of people called "Mountain Men", by people living in the East. The job of these people was to hunt beavers. Why? In the 1800s, beavers were very demanding. Their furs were used as clothing (or hats, blankets, etc.), which were "in fashion" at that time. The mountain men must push westward, since beavers are extinct in Europe and have also been exterminated in the East, due to their ever-increasing popular demand. Rocky Mountain beavers were their target. Embarking on this journey has its pros and cons for mountain men. First of all, they traveled to make money for themselves and their family, and they also tell stories about their journey, many of which were sold in books, making the idea of ​​​​the expansion of the Western world more popular, inspiring families and people to move there. the West for itself. But during this journey, these men faced many hardships, requiring... half paper... 2,000 men and many weapons. The United States also bombed the city from the sea. They continued to advance towards Mexico City. After a long battle, Mexico City surrendered. On February 2, the Treaty of Guadalupe Hidalgo was signed between the United States and Mexico. Having the United States own California, Nevada, Arizona, New Mexico, Utah, Colorado, Wyoming, and Texas, while agreeing to respect the Mexican citizens still living in these states. All of these events were part of the expansion, from the beginning of Mountain Men, to the Mexican-American War. Proving that America has grown and changed tremendously in just under a decade. Show the power and development of America. How they won many battles and earned their land. Prove that they are superior, as if it were their destiny, but it seems like it is. Without these events, America would not be like itself today.