Due to rich stands of virgin timber, lumbering became a major industry, and a railroad spur soon linked Fremont to the national rail network. The lumbering industry declined in the 1860s because of the American Civil War; and in 1871, Fremont experienced a major forest fire that caused extensive damage, especially to the lumber mills. Nevertheless, Fremont rebuilt and was even able to supply some lumber to rebuild Chicago after the Great Fire of 1871.