When did the United States open its immigration?

It should start in May of 1830 and end in 1860. You can look at the following information: \x0d\ The development of the western region of the United States is also called the westward movement. \x0d\ As early as the colonial period in North America, western accommodation began. Slave owners in the south, land speculators and poor people in the north all hope to acquire land in the west. In order to limit the colonial people to the places under their control, the British government issued a notice in 1763, prohibiting immigrants from crossing the west of the Appalachian Mountains. The revolution of independence broke this rule. 1783, Britain and the United States negotiated a peaceful settlement, and Britain opened a large area of Indian-owned land from the west of the Appalachian Mountains to the Mississippi River to the United States. 1830 In May, President A. Jackson passed the Indian Migration Act to move Indians to the west of the Mississippi River. Later, he sent troops to escort the Indians out of the area east of the Mississippi River, and the colonial cause developed rapidly in this area. The land in the "Old Southwest" (including Kentucky, Tennessee, Alabama, Missouri, Mississippi, Arkansas and Louisiana) was mainly occupied by plantation slave owners and became the main cotton producing area. The colonial development of "Old Northwest" (including Ohio, Indiana, Illinois, Michigan and Wisconsin) developed rapidly because of the land regulations (selling public land at low prices) passed by 1785 and the northwest territory regulations of 1787. At the beginning of the revolution of independence, there were only a few thousand French people here. 18 10 has more than 270,000 immigrants, and 1860 has increased to 6.93 million, and the population of Chicago alone has 1 10,000. This is a region rich in grain and developed in aquaculture. \x0d\ At the same time, the United States also expanded to the west of the Mississippi River, annexing French, Spanish and British colonies and large areas of Mexico by means of purchase and war. 1803, when Napoleon was busy coping with the European war, the United States bought a vast area called Louisiana (with an area of about 830,000 square miles) from France for150,000 dollars. The United States seized Florida from Spain in 18 10 and 18 19; 1846, Britain was forced to sign a contract to extend the U.S. border at 49 degrees north latitude to the Pacific coast and exclude the British from this area. 1846 and 1853, the United States launched a war with Mexico, and after the victory, it bought a large area of land in Mexico, totaling about 950,000 square miles. By 1853, the United States had pushed its border to the Pacific coast, covering an area of 3.03 million square miles (about 7.85 million square kilometers), more than seven times the territory when it declared independence. The population to the west of the Mississippi River was extremely scarce before 1840, and immigrants began to increase in the 1940s, especially the discovery of the California gold mine in 1848, which greatly promoted the development of the western region. After 1850, the immigration and economic development in this area played an important role in the development of the United States. In addition, the United States continues to expand westward to areas that are not adjacent to the mainland. In 1867, Alaska bought it from Russia for 7.2 million dollars, which was twice the area of the original 13 state in the United States. 1894, the United States overthrew the king of Hawaii in Honolulu. 1898, after the Spanish-American War broke out, it annexed the Hawaiian islands. \x0d\ The territory of the United States continues to expand, attracting a large number of foreign immigrants. 1790- 1860 has more than 5 million immigrants,1861-1913 years, 27 million. The population west of Appalachian Mountains accounted for only 3% of China's total population in 1790, and increased to 49% in Indian year 18. Foreign immigrants have played a great role in the western development and the rapid development of the entire American economy. Immigration enabled the United States to carry out large-scale agricultural production and develop its rich industrial resources with great strength and scale, which quickly destroyed Britain's industrial monopoly position. The land policy of the American government and the construction of the transcontinental railway accelerated the development of the western region. The territorial expansion and development of the United States to the west has had a great impact on American political and economic life. The incorporation of the vast western land into the United States has made the United States a country with a vast territory and rich natural resources, and has extremely superior natural conditions for economic development. Greatly expanded the arable land area, located in the climate zone suitable for farming, so that agriculture developed rapidly; The large-scale development of the western region has led to large-scale railway construction and the influx of immigrants, forming a vast domestic market in the United States. But it is undeniable that the westward movement is also a history of American Indians' blood and tears.