Cholera outbreaks and pandemics
That year, cholera was transmitted along the California, Mormon and Oregon Trails as 6,000 to 12,000 are believed to have died on their way to the California Gold Rush, Utah and Oregon in the cholera years of 1849–1855. It is believed more than 150,000 Americans died during the two pandemics between 1832 and 1849.
Oregon Trail
Some of the trail statistics for the early years were recorded by the U.S. Army at Fort Laramie, Wyoming, from about 1849 to 1855. None of these original statistical records have been found—the Army either lost them or destroyed them. Only some partial written copies of the Army records and notes recorded in several diaries have survived.