Milton graduated from Hamilton College, Utica, New York; also in the medical profession. Finding his practice too arduous, he embarked in a mercantile career, but resumed his practice again in Chicago, Illinois, before his death. He was for many years a merchant in Zanesville, Ohio. He also took a prominent part in educational matters, and was one of the pioneers in the anti-slavery and temperance movements.
In 1819 Milton entered Hamilton Literary and Theological Institute, a Baptist college in Hamilton, New York, which grew to become Madison College and eventually Colgate University. He wanted to become a doctor. But because he suffered from tuberculosis, a disease he may have contracted from his mother, he was unable to complete his schooling, although he often referred to himself in later life as "Dr. Cushing."
At his funeral a eulogist said "He was a man of elevated character, deep piety, acute and vigorous intellect. His influence was felt wherever he was known. As a business man he was energetic, persevering and clear-sighted. As a friend, he was constant, devoted and self-sacrificing. As a man he was full of benevolence and active charity. The poor found in him a ready benefactor and the oppressed a strong and unflinching advocate. He was a conscientious and active antislavery man and gave liberally of this money, and his time and thought, to assist in bringing freedom to the colored race. He was a handsome man of fine presence and was a society favorite. His death was deeply mournedby those whose affection his kindness had won and whose regard his sterling qualities had secured."

Milton was not robust [had TB], "practiced" a few years in Ohio then moved to wilds of Wisconsin near Milwaukee with MIlton Jr and children from first marriage. Family histories all cite him as physician, but Hamilton College was only open 1 year before he moved to Ohio. No record there ofhis graduation. Probably was store keeper in Ohio and fairly certainly not a physician.
1839 they went to log cabin few miles north of Waukesh Wisconsin, halfway between Lakes Nemahbin and Nagawick, no. of Bark R., now village of Delafield. By 1844 the outdoor existence was too strenuous -- moved to Chicago Illinois. He lived on the waterfront. 1846 worse, decided to travel to visit cousin Judge L. S. Houghton of Vicksburg, Michigan. Then he removed to Columbus Ohio; then in Galllipolis, Ohio his cold went to pneumonia in hotel bedroom. Wife (Mary Barker) accompanied the body to Fredonia where he was buried.
He was a pioneer in anti-slavery and temperence movements.

Sources:
1. The Genealogy of the Cushing Family (An account of the Ancestors and Descendants of Matthew Cushing, who came to America in 1638) by James Cushing, The Perrault Printing Co - Montreal, 1905. First Edition, 1877, by Lemuel Cushing, D1881 (Finished by his family) Pg 134.
2. Cushing of Gettysburg, The Story of a Union Artillery Commander; Kent Masterson Brown, Univ. Press of Kentucky, 1993. Copy in Diane Rogers Carroll library
3. Lincoln's Commando by Ralph J. Roske and Charles Van Doren, published by Harper & Brothers, New York 1957.
Library of Congress catalog number: 56-11083
4. FamilySearch™ Pedigree Resource File

• Married: 12 Jun 1836 in Baptist Church, Columbus, Franklin, Ohio

1. Milton Buckingham Cushing b: 20 Apr 1837 in Columbus, Franklin, Ohio
2. Howard Bass, Lieutenant Cushing b: 22 Aug 1838 in Delafield, Waukesha, Wisconsin
3. Walter Cushing b: 28 Dec 1839 in Milwaukee, Milwaukee, Wisconsin
4. Alonzo Hereford (Lon), Lieutenant Colonel, Captain Cushing b: 19 Jan 1841 in Milwaukee, Milwaukee, Wisconsin
5. William Barker, Commander Cushing b: 4 Nov 1842 in Delafield, Waukesha, Wisconsin
6. Mary Rachel Cushing b: 1 Oct 1845 in Chicago, Cook, Illinois
7. Mary Isabel Cushing b: 1 Jan 1847 in Chicago, Cook, Illinois

• Married: 25 Nov 1823 in Zanesville, Muskingum, Ohio

1. Benjamin Tupper Cushing b: 25 Jun 1825 in Zanesville, Muskingum, Ohio
2. Edward Anselm, Dr. Cushing b: 26 Sep 1827 in Zanesville, Putnam, Ohio
3. Rowena Sophia Cushing b: 29 Mar 1829 in Zanesville, Putnam, Ohio
4. Abigail Elizabeth Cushing b: 3 Oct 1833 in Zanesville, Muskingum, Ohio