Thomas Evans Cochran was the son of Dr. Richard Ellis and Eliza Frances (Evans) Cochran. His father was one of the early graduates from the Medical Department of the University of Pennsylvania and practiced medicine at Middletown, Delaware, until the year 1824, when he moved to Columbia, Pennsylvania, where he continued to practice his profession until the time of his death in September, 1854, when he fell a victim to the epidemic of Asiatic cholera which prevailed in that town.
Thomas Evans Cochran was born near Middletown, Delaware, on March 23, 1813. He attended the Newark (Delaware) Academy and when ten years of age went with his parents, who moved to Columbia, Pennsylvania, where he grew up. While he remained in Columbia he became the assistant editor and afterward editor of "The Columbia Spy." About 1834 he moved to York, Pennsylvania, and became the editor and one of the publishers of the "York Republican." He was a member of the Senate of Pennsylvania during the sessions of 1840, 1841, 1842 and 1843, and was elected auditor-general of Pennsylvania in 1859—the first Republican to be elected to a State office in that Commonwealth—and his election in 1859 State of Pennsylvania made possible the election of Andrew G. Curtin to the office of Governor in October, 1860, and of Abraham Lincoln the following November. As a Whig Mr. Cochran represented his Congressional District in the National Convention of that party in 1840, and as a Republican he was a delegate to the National Conventions of the party in 1860, 1864 and 1868. Mr. Cochran entered upon the study of law under the praceptorship of the Hon. Charles A. Barnitz, a distinguished member of the bar of Pennsylvania, and was admitted to the bar on December 6, 1842. He immediately entered upon the practice of his chosen profession and for almost forty years served a large clientele, with distinguished success. His high personal character, great intellectual ability and legal attainments, gave him a high place at the bar of his State and in the community in which he lived. On April 1, 1860, before entering upon his official duties as auditor-general, Mr. Cochran entered into a partnership in the practice of law with William Hay, Esq., one of the younger members of the bar of York county, and that partnership continued until the death of Mr. Cochran.
Mr. Cochran was a member of the convention which prepared the present Constitution of Pennsylvania and was one of two members of that body who served upon three of its standing committees. He was chairman of the important committee on Railroads and Canals, and also served on committees on Accounts and Expenditures, and on Printing and Binding. He was a member of St. John's Episcopal Church of York, and for many years served as a vestryman of that church.
On April 14, 1853, Mr. Cochran was married to Anna Maria Barnitz, of York, Pennsylvania, who died in January, 1882, aged sixty-two years. Four children were born of this marriage: Eliza Evans and Alice Lisle, who are now deceased; and Emma Barnitz and Richard Ellis, who are still living.