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 was the transcontinental railroad started and finished?" whose answer is between 1863 and 1869.
Each document should contain about 30 words, and these documents should contain useful information.

Query: transcontinental railroad start and finish dates
Useful Output:

Doc 1: On May 10, 1869, at 12:47 p.m., the final spike was driven into the last bit of track. Called the “Golden Spike Ceremony”, the last spike linked
Doc 2: 1863: Union Pacific incorporated in New York. 1869: First transcontinental railroad completed. 1872: Credit Mobilier of America — the
Doc 3: Completion of the Transcontinental Railroad on May 10, 1869, reduced the travel time from New York City, New York to San Francisco, California
Doc 4: Travel back time and learn about key events surrounding the Transcontinental Railroad, from 1769 to 1889.
Doc 5: Workers completed the line on May 10, 1869, 150 years ago today. “Next to winning the Civil War and abolishing slavery, building the first