To Powell was assigned the department of conchology.

This work he entered upon with his usual application and made the most complete collection of the mollusca of Illinois ever brought together by one man.

Incidentally, botany, zoology, and mineralogy received attention, and in these lines he secured notable collections.

With the broad mental grasp which was a pronounced trait, he perceived that these studies were but parts of the greater science of geology, which he then announced, to at least one of his intimate friends, was to be the science to which he intended to devote his life.

The next year was given to study, teaching, and lecturing, usually on some topic connected with geology.
In the spring of 1860, on a lecturing tour, he visited some of the Southern States, and while there closely observed the sentiment of the people on the subject of slavery, with the result that he expressed the conviction that nothing short of war could settle the matter.