The 24th Lucas County Prosecutor was born in Logan County, Ohio in 1867, the son of a Presbyterian minister of Scottish ancestry. An 1892 graduate of Ohio Northern University, Ada, Ohio, he embarked upon an educational career as a school superintendent in McComb, Ohio, upon graduation. From his savings, he worked his way through the University of Michigan law School, from which he graduated with an LLB in 1897.

He moved to Toledo and embarked on a highly successful career in law and public service. He practiced law with Brand Whitlock, another prominent Toledoan. For eight years, he was a Trustee of the University of Toledo (then called Toledo University). In 1912, he was elected Mayor of Toledo and served during 1916-1917, being the first Mayor to serve under the new Charter form of government.

In 1920, Milroy was elected to the Lucas County Common Pleas Court in 1920, where he continued to serve until his death. He was Presiding Judge of the Court when he died in 1931.

It was said of him: "Mr. Milroy's course in public life has been marked by strong independence. He has always surrounded himself with able assistants and advisors." (History of Northwest Ohio, Williams, pp. 738-739).

His was a well-respected reputation for both humanity and impartiality:

"Judge Milroy mixed with his impartial spirit and his unyielding respect for the law a warm-hearted humanity that endeared him to the public." (News Bee, 12/14/31).