which had evidently been dormant in his mind since the days of
his early Mississippi River experiences. The little model of a
boat, whittled out with his own hand, that he sent to the Patent
Office when he filed his application, is still shown to visitors,
though the invention itself failed to bring about any change in
steamboat architecture.

In work and study time slipped away. He was the same cheery
companion as of old, much sought after by his friends, but now
more often to be found in his office surrounded by law-books and
papers than had been the case before his term in Congress. His
interest in politics seemed almost to have ceased when, in 1854,
something happened to rouse that and his sense of right and
justice as they had never been roused before. This was the repeal
of the "Missouri Compromise," a law passed by Congress in the
year 1820, allowing Missouri to enter the Union as a slave State,
but positively forbidding slavery in all other territory of the
United States lying north of latitude 36 degrees 30 minutes,
which was the southern boundary-line of Missouri.

Up to that time the Southern States, where slavery was lawful,
had been as wealthy and quite as powerful in politics as the
Northern or free States. The great unoccupied territory lying to
the west, which, in years to come, was sure to be filled with
people and made into new States, lay, however, mostly north of 36
degrees 30 minutes; and it was easy to see that as new free
States came one after the other into the Union the importance of
the South must grow less and less, because there was little or no
territory left out of which slave States could be made to offset
them. The South therefore had been anxious to have the Missouri