Dr. Mark Thomas Sheehan, a physician of Wallingford, who in May, 1917, enlisted in the Medical Officers' Reserve Corps of the United States army, was born in Pittsfield, Massachusetts, February 22, 1885. His father, Jeremiah Sheehan, is also a native of that place and devoted his active business life to merchandising but is now living retired in Pittsfield. He wedded Mary Coughlan, a daughter of Thomas Coughlan, while the paternal grandfather was Daniel Sheehan. Both the paternal and maternal grandparents of Dr. Sheehan came from Ireland. The family of Mr. and Mrs. Jeremiah Sheehan numbered six children, all of whom are residents of Wallingford.

At the usual age Dr. Sheehan became a pupil in the Wallingford schools, passing through consecutive grades to the high school, while later he studied in the Holy Cross Preparatory School and College of New Haven. After two years there passed, he entered Yale as a medical student and completed the regular four years' course, being graduated with the M. D. degree as a member of the class of 1910. During the following year he was connected with St. Francis Hospital and in 1912 was made superintendent of the Hartford State Tubercular Sanitarium. For a year he continued in practice in Hartford, and in April, 1914, opened an office in Wallingford, where he has since remained, devoting his attention to general practice, in which he has been very successful. Realizing fully the duties and obligations which devolve upon him in his efforts to restore health and check the ravages of disease, he has put forth every possible effort to promote his knowledge and thus advance his efficiency. He has taken post-graduate work in the Manhattan Eye and Ear Hospital, has also made a special study of diseases of the nose and throat and in the line of his specialty has made substantial and rapid progress.

Dr. Sheehan is a communicant of the Holy Trinity church. His political allegiance is given to the democratic party but he is not an active worker in its ranks. He belongs to the Wallingford Medical Society, the New Haven County Medical Society, the Connecticut State Medical Society and the American Medical Association. As stated, he enlisted in May, 1917, in the Medical Officers' Reserve Corps of the United States army for service in France and he has responded to the call of duty that his country issued. America feels a thrill of pride in all of those who have offered to aid in the gigantic task of making the world safe for democracy and none deserve in greater degree the gratitude and honor of their fellowmen than the physicians and surgeons, whose position is often more difficult and whose tasks more heartrending and who are often more exposed to danger than the men of the first line trenches.