He came to the US with his family in 1842. 
They had one daughter, Bertha Mabel (Langwill) 1874 - 1929.
He is mentioned in The Scots and their Descendants in Illinois By Thomas C. MacMillan, M.A., LL.D.:
Among the young men who grew up in this church, was Rev. John A. Montgomery. He was a son of Elder Eldder James Montgomery and his wife Jane Caldwell, Montgomery was born in Argyllshire, Scotland, December 18, 1839, and came to the United States with his parents when a child. He was educated in the Marengo Academy, in Wheaton College, and in the Chicago Congregational Theological Seminary, at Union Park. He graduated with the highest honors from college and academy. The late venerable President Franklin W. Fisk of the latter institution was ever a warm personal friend of Mr. Montgomery, and expressed his deep appreciation of him to the effect that "you (Mr. Montgomery), have been a constant joy to me all the years since you went from the Seminary." Mr. Montgomery served in the active ministry for twenty-five years, in three Congregational Churches—Dwight, Morris, and LaGrange. In his pastorates, he drew about him, men like Dr. Keeley, Edward Kemeys, the sculptor of the lions in front of the Art Institute, Chicago; Gen. P. C. Hayes, Member of Congress; Justice Orrin N. Carter, of the State Supreme Court; F. D. Cossit, the Founder of LaGrange; George M. Vial, Moderator of the Illinois Congregational Conference; and Rev. J. C. Armstrong, D. D., of the well known Armstrong family of La Salle County, and for more than a third of a century Superintendent of the Congregational City Missionary Society of Chicago. Mr. Montgomery was always a close student, an indefatigable worker, and was held in high esteem by his ministerial brethren. He was an honored official of the State Congregational Association, and was a delegate from Illinois to the First National Council of Congregational Churches, in 1871.
He died in 1907.
See also: Find A Grave: Memorial #88878725
"United States Census, 1900," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:MS7N-HYC : accessed 18 June 2018), John Montgomery, Lyons Township La Grange village, Cook, Illinois, United States; citing enumeration district (ED) 1169, sheet 42A, family 725, NARA microfilm publication T623 (Washington, D.C.: National Archives and Records Administration, 1972.); FHL microfilm 1,240,293.
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John is 23 degrees from Claude Monet, 19 degrees from Gigi Tanksley and 20 degrees from Victoria of the United Kingdom of Great Britain and Ireland on our single family tree. Login to find your connection.