You are the Google search engine.
Given a query, you need to generate five useful documents for the query.

The user is trying to answer the question: "when did the us acquire the us virgin islands?" whose answer is 1917.
Each document should contain about 30 words, and these documents should contain useful information.

Query: when did the us acquire the us virgin islands
Useful Output:

Doc 1: The islands became US territory in 1917 when they were purchased from the Kingdom of Denmark for $25 million in gold. It was during World War I.
Doc 2: After decades of negotiations, the United States purchased the islands in 1917. The United States Virgin Islands officially became an unincorporated U.S.
Doc 3: The United States took possession of the islands on March 31, 1917, and the territory was renamed the Virgin Islands of the United States. Every year, Transfer
Doc 4: 24 Jan 1902 Second U.S. attempt to purchase the islands. 22 Dec 1916 Purchased from Denmark by United States.  (Virgin Islands of the United States). 31 Mar
Doc 5: The islands were purchased from the Danish by the United States in 1917. Under the Treaty of the Danish West Indies.