Rumor Mill

Despite Marshall (and Sutter) trying to keep a tight lid on news of the discovery, rumors started to spread. In March 1848, a local newspaper publisher and merchant named Samuel Brannan published the news; he even went so far as to start selling gold-prospecting supplies.
However, it was still the mid-1800s, so it would take another three months for the news to reach the East Coast, and almost four more months before President James Polk confirmed it during a Congressional address.
The above photo is of the title page of Travel & Gold Rush Guide, written by L. W. Hastings and published in Cincinnati in 1849.