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: "where did they start building the transcontinental railroad?" whose answer is 1863.
Each document should contain about 30 words, and these documents should contain useful information.

Query: when and where did construction of the transcontinental railroad begin
Useful Output:

Doc 1: Their task was to build a transcontinental railroad that would link the United States from East to West. Over the next seven years, the two companies raced
Doc 2: The Central Pacific Railroad Company started construction of the Transcontinental Railroad  The first rails were spiked in January of 1863.
Doc 3: While B&O Railroad was the first commercial transportation by rail in 1827, connecting Chicago to the East Coast, there still was not a direct
Doc 4: It was the moonshot of the 19th century – crews working East from Sacramento and West from Omaha to build the Transcontinental Railroad,
Doc 5: The Transcontinental Railroad was completed in 1869. But it was a hard-won success, with the final 700 miles of track being built almost entirely by skilled