Mechlin was art critic for the Washington Evening Star from 1900 until retiring in June 1946.

She felt that these characteristics were embodied in traditional art, in the evolution from the kind of work which ‘generations had agreed to admire,’ more often than in the experimental work that stemmed from the ‘School of Paris’ and the Armory Show.

She had deep convictions and the moral courage to fight for them.”[3]In 1909, Mechlin was a cofounder (with figures like Andrew Mellon, J. P. Morgan and Presidents William Howard Taft and Theodore Roosevelt) of the American Federation of Arts, intended to promote American art and particularly touring of American art exhibitions to more remote parts of the United States; Mechlin served as its secretary until 1933.

[2] She was a contributor to Funk & Wagnalls Yearbook, the Encyclopædia Britannica,[4] and the Dictionary of National Biography.

[5] Leila Mechlin was elected a fellow of the Royal Society of Arts in London in 1940.