What is the largest territory acquired by the United States?

The largest territory acquired by the United States is Alaska. It was purchased from Russia in 1867 for $7.2 million, which is often regarded as a significant bargain given its vast resources and land area. Alaska spans about 663,000 square miles, making it far larger than any other U.S. state, which contributes to its status as the largest territory acquired.

Other territories, while significant in their own right, are much smaller in comparison. Texas, for example, was an independent republic before joining the United States and covers approximately 268,000 square miles. California, acquired in the mid-1800s during the Mexican-American War, has an area of around 163,000 square miles. Florida was acquired from Spain in 1819 and has a land area of about 65,000 square miles. Hence, while these territories are notable for their historical and economic importance, none of them surpass Alaska in size.