John Osborne and James W. Gerencser, eds., “John Andrew Jackson Creswell,” Dickinson Chronicles, http://chronicles.dickinson.edu/encyclo/c/ed_creswellJAJ.htm.
He joined the Maryland bar in 1850 and began to practice in Elkton. Entering politics first as a Whig and then as a Democrat, he was a delegate in 1856 to the Democratic National Convention which nominated his fellow alumnus, James Buchanan, as presidential candidate. In 1861 he himself was elected to the Maryland House of Representatives and then in 1862 to the U.S. Congress for his home district of Cecil County, though by now he had affiliated himself with the Republican Party. He rose to prominence with two speeches in support of African American participation in the life of the nation; one supported the enlistment of black soldiers in the service of the Union and the other an eloquent support for the Emancipation Proclamation. Soon after this he was named to fill a vacancy in the United States Senate and served there from 1865 to 1867. In 1866 he was a prominent delegate at the convention of Southern Loyalists in Baltimore where he supported for tactical reasons the opposition to negro suffrage in border states, though he was generally always in support of equal political rights. His name was placed in nomination as Vice President in the Chicago convention of 1868 but he declined and supported Benjamin Wade. He was appointed to President Grant's cabinet as Postmaster General in 1869 and served with distinction until 1874 as the longest serving cabinet member of the two administrations. While responsible for the nation's mails, he ended the franking privilege, reformed letter delivery, and fought unsuccessfully for a system of U.S. Post Office telegraphical delivery. A trusted and close friend of President Grant - Creswell and his wife were at Grant's bedside when he died in 1884 - he served as U.S. Counsel for the Court of Commissioners of Alabama Claims and as one of the commissioners that closed up the dealings of the Freedmen's Savings and Trust Company. He then resumed his law practice and served from 1875 as the president of the Citizen's National Bank in Washington D.C..
A strong supporter of his old College, Creswell was a trustee of the College from 1865 to 1871, and then was elected again in 1885. Creswell was an active Presbyterian. He had married a Miss Richardson of Elkton but the couple had no children. John A. J. Creswell died suddenly at his home a mile outside Elkton, a victim of heart trouble and a mild pneumonia on the late morning of December 23, 1891. He was sixty-three years old.