Mississippi River finds its sources, and secured his appointment as
second lieutenant of topographical engineers. These labors brought him
to Washington, where the same Gallic restlessness which made the
restraint of schools insupportable, brought about an attachment,
elopement, and marriage with the daughter of Senator Thomas H. Benton,
of Missouri.

Reconciliation followed in good time; and the unexplored Great West
being Benton's peculiar hobby, through his influence Frémont was sent
with an exploring party to the Rocky Mountains. Under his command
similar expeditions were repeated again and again to that mysterious
wonderland; and never were the wildest fictions read with more avidity
than his official reports of daily adventure, danger and discovery, of
scaling unclimbed mountains, wrecking his canoes on the rapids of
unvisited rivers, parleying and battling with hostile Indians, and
facing starvation while hemmed in by trackless snows. One of these
journeys had led him to the Pacific coast when our war with Mexico let
loose the spirit of revolution in the Mexican province of California.
With his characteristic restless audacity Frémont joined his little
company of explorers to a local insurrectionary faction of American
settlers, and raised a battalion of mounted volunteers. Though acting
without Government orders, he cooperated with the United States naval
forces sent to take possession of the California coast, and materially
assisted in overturning the Mexican authority and putting the remnant
of her military officials to flight. At the close of the conquest he
was for a short time military governor; and when, through the famous
gold discoveries, California was organized as a State and admitted to
the Union, Frémont became for a brief period one of her first United
States Senators.