I had seen in the South, the emotional side of the character of the American born negroes, as shown in their political meetings and their religious services, but I had not been previously aware that these apparently lethargic people had by nature, the capacity for becoming brave and impulsive soldiers. It is obvious that they felt they were fighting for freedom, and for the emancipation of their wives and children, the most powerful incentives that could stimulate their actions. They were ready and willing to face the risk of death in order to obtain that freedom which, to those that have it not, must be the most coveted prize that this world can give. One afternoon I went to Cambridge for the purpose of meeting Mr. Bartlett, a partner in the publishing firm of Messrs. Little and Brown. I was indebted to him for many kind acts in assisting me in visiting the museums, and we had arranged to go to the Harvard University together, in order to have an interview with Professor Agassiz, who had returned from Florida, where he had been engaged in the examination of the coral reefs. After looking at the extensive collection of corals and shells which had been placed in the Museum, we walked across the college grounds to the Professor’s house. I delivered my letter of introduction, and was received with great courtesy. Agassiz for some time talked about his varied experiences in many parts of the world and his recent researches, but upon hearing that I was going to visit the prairies in the North-west, he showed much interest in the details of the journey that I proposed to take. He said that he had been in many parts of those prairies, and had made several careful investigations with the object of establishing certain facts with regard to their formation, and had come to the conclusion that they were caused by glacial action. He thought that the theory that they were once sea beaches was erroneous, for he was convinced that the sea had never been in those regions. He also spoke about the consequences of the habits of the numerous herds of buffaloes that had roamed, in remote times, over those lands and had made their wallows there. These shallow depressions collected large quantities of water, and influenced the manner in which many of the streams originated.