Mr. Blackall was educated in New York, and in preparation for an architectural career studied at the University of Illinois, with three supplementary years of training in France at the Ecole des Beaux Arts in Paris.
He worked as draftsman for a time in New York, but left the city in 1884 to settle in Boston. While employed with the firm of Peabody & Stearns, he was successful in winning the Rotch Travelling Scholarship, the first American student to have that distinction. With the advantage of two years of travel and study in Europe, Mr. Blackall returned to Boston prepared to begin practice, and in 1889 joined James F. Clapp and Charles A. Whittemore in organizing the firm with which he was connected during the rest of his career. The first important commission awarded the partners was to plan the Bowdoin Square Theatre, and in the following years Mr. Blackall was identified with the design of a number of other theatres in Boston, including the Tremont, the Colonial, the Wilbur and the Metropolitan. One of his outstanding works was the Tremont Temple, home of the Baptist Church in Boston, and with his partners planned other public and commercial buildings in the city. Among these should be named the Carter Building (an early work completed in 1894); the Lowell Auditorium; Castle Square Theatre and Hotel; Little Office Building (1916-17); and three newspaper buildings, the Boston Herald, Boston Post, and the Boston American. One of his late important works was the Ohabel Shalom Temple at Brookline. In addition to the above Mr. Blackall served as Consulting Architect on the new Copley Plaza Hotel in Boston, designed by H. J. Hardenbergh of New York.
Prominent professionally, he was an early member of the Boston Society of Architects, A.I.A., raised to Institute Fellowship in 1891. He was one of the organizers and the first President of the Boston Architectural Club, a founder and the first Secretary of the Architectural League of New York, and belonged to many other professional groups.