In 1869, he made a trip to the South for the purpose of examining its resources; and in 1870, with a large party, he visited California. The result of Mr. Wilder's observations have been given to the public in a lecture before the Massachusetts state board of agriculture, which was repeated before the Boston Mercantile Library Association, the Amherst and the Massachusetts Agricultural colleges, Dartmouth College, the Horticultural Society, and the merchants of Philadelphia, and bodies in other places. His published speeches and writings now amount to over eighty in number. A list to the year 1873 is printed in the "Cyclopedia of American Literature." Dartmouth College, as a testimonial to his services in science and literature, conferred upon him, in the year 1877, the degree of Doctor of Philosophy. The Hon. Paul A. Chadbourne, LL. D., late president of Williams College, in a recent memoir of Mr. Wilder remarks: "The interest which Col. Wilder has always manifested in the progress of education, as well as the value and felicitous style of his numerous writings, would lead one to infer at once that his varied knowledge and culture are the results of college education. But he is only another illustrious example of the men who, with only small indebtedness to schools, have proved to the world that real men can make themselves known as such without the aid of the college, as we have abundantly learned that the college can never make a man of one who has not in him the elements of noble manhood before he enters its halls." In 1820, Mr. Wilder married Miss Tryphosa Jewett, daughter of Dr. Stephen Jewett, of Rindge, a lady of great personal attractions. She died on a visit to that town, July 21, 1831, leaving four children. On the 29th of August, 1833, Mr. Wilder was united to Miss Abigail, daughter of Capt. David Baker, of Franklin, Mass., a lady of education, accomplishments, and piety, who died of consumption April 4, 1854, leaving five children. He was married a third time on the 8th of September, 1855, to her sister, Miss Julia Baker, who was admirably qualified to console him and make his dwelling cheerful, and who has two sons, both living. No man has been more blessed in domestic life. We know not where there would be a more pleasing picture of peace and contentment exhibited than is found in this happy family. In all his pursuits and avocations, Mr. Wilder seems to have realized and practiced that grand principle which has such a bearing and influence on the whole course of life,--the philosophy of habit, a power almost omnipotent for good or evil. His leisure hours he devotes to his pen, which already has filled several large volumes with descriptions and delineations of fruits and flowers proved under his own inspection.