The declaration was followed by a six year War of American Independence.
During the 19th Century the USA acquired territory in North America through wartime conquest, with Native Americans and with Mexico, and through purchase of the Louisiana Territory from France, and throught the purchase of Alaska from Russia. In 1898 The USA entered int the Spanish American War and acquired former Spanish colonies, including Cuba, Puerto Rico, Guam, the Philippines, and what is now American Samoa and the American Virgin Islands.
The United States was a slave-owning country, from its founding to 1865.
During the 19th Century the United States went from a industrially backwards country to a country with one of the World`s greatest Gross National Products.
- David E. Shi (2011-07-01). "A war of independence that divided American colonies". Atlanta Journal Constitution. https://www.ajc.com/opinion/a-war-of-independence-995679.html. Retrieved 2012-06-24.
- "Constitution of the United States". http://www.archives.gov/exhibits/charters/constitution.html/. Retrieved 2012-06-24. "The Federal Convention convened in the State House (Independence Hall) in Philadelphia on May 14, 1787, to revise the Articles of Confederation."
- "150th Anniversary of the Bill of Rights is Commemorated". Evening Standard. 1941-12-15. http://news.google.com/newspapers?id=uPdPAAAAIBAJ&sjid=J1UDAAAAIBAJ&pg=4259,2554961&dq=united+states+bill+of+rights&hl=en. Retrieved 2012-06-24. "It was Virgina which voted on Dec. 15, 1791, the final state ratification necessary to make the bill of rights the law of the land."