He was also editor of the Minneapolis Tribune, and from late 1887 to 1888 Commander-in-Chief of the Grand Army of the Republic, succeeding Lucius Fairchild.

Rea was a native of the state of Pennsylvania, born October 13, 1840, in Lower Oxford Township, Chester County.

Grandfather Samuel Rea (1756–1816), brother to John Andrew Rea’s great grandmother Barbara, was a private in Captain Thomas Whiteside’s Company, Colonel Thomas Porter’s Battalion, Pennsylvania militia, fighting in the battles of Trenton, Princeton, Brandywine, Germantown and Monmouth; Samuel wintered at Valley Forge with General George Washington, assigned to the "fire detail" faking encampment while the Continental Army broke camp to avoid General Cornwallis and secure Princeton.

On April 17, 1861, John P. Rea enlisted as a member of Company B of the Eleventh Ohio Infantry.

Major Rea served continuously in the Army of the Cumberland until November 24, 1864, when he was obliged to resign due to poor health.

Rea associated with M. J. Dickey, Esquire, who later replaced the late Thaddeus Stevens as a Member of the U. S. House of Representatives.

On April 7, 1869, Mr. Rea was appointed Assessor of Internal Revenue, 9th Pennsylvania District, by President Ulysses S. Grant, an office he held until it was abolished by law on May 12, 1873.

[4] In November 1877, he was elected Judge of Probate, Hennepin County, Minnesota, and served in that capacity until December 31, 1881.

[6] He is buried beneath a monument in the Little Britain Presbyterian Church cemetery in southern Lancaster County, Pennsylvania, about three miles west of his place of birth, the same hometown as John Andrew Rea.