In 1872, Elijah applied for and received his first patent. 
Elijah and Kitty (his daughter) were living in Ionia, Ionia County, Michigan, in 1880,  most likely a site of Elijah's inventions-in-use. 
On 2 Nov 1895, Elijah was in a newspaper article, in The Afro-American, which reported that he lived in Detroit (Wayne County, Michigan). 
Elijah and Mary are found on the census for 1900, in Detroit, Wayne County, Michigan.  By 1910, Elijah reported he was married twice, once for 3 years and the next for the past 7 years.  His last census was 1920. 
He died on October 10, 1929 in Nankin, Wayne County, Michigan, with his usual residence in Detroit (also in Wayne County). He is remembered in the Detroit Memorial Park East, Warren, Macomb County, Michigan, USA. 
"Though it has been written otherwise, Elijah McCoy was not from Kentucky. He was born in Ontario, Canada. McCoy was the son of Mildred and George McCoy, escaped slaves from Louisville, KY. Elijah was a mechanical engineer known as the "Father of Lubrication." In 1872 he first patented an invention for self-oiling machines; automatic lubrication became known as "the real McCoy." He also invented an ironing table and lawn sprinkler. For more see World of Invention. History's most significant inventions and the people behind them, 2nd ed." 
Elijah McCoy was from Canada. His parents were former slaves in the South (USA).
Elijah was known for his development of 57 patents, including a cup that fed lubricating oil to machine bearings through a small bore tube. It was known as an ‘automatic oil cup’ and would become standard equipment on all trains.
While working as a locomotive fireman and oiler for the Michigan Central Railroad he saw a need. A fireman on a train was responsible for fueling the steam engine and the oiler lubricated the engine's moving parts as well as the train's axles and bearings. Because of his training, Elijah was able to identify and solve the problems of engine lubrication and overheating. He developed a lubricator for steam engines that did not require the train to stop. His lubricator used steam pressure to pump oil wherever it was needed. Elijah’s first patent was official on July 12, 1872 with additional improvements coming over the years.
Years later Elijah opened his own company named, Elijah McCoy Manufacturing Company in Detroit, Michigan in 1920. They manufactured and sold his advanced graphite lubricators for air brakes. 
↑ 1.01.1 * 1843 birth, parents, * 1929 death: Elijah McCoy death certificate, #282 2335, 10 Oct 1929 Wayne County, Michigan; normal residence 606 Hendrik, Detroit, Michigan; place of burial Detroit, Wayne County, Michigan; born 27 Mar 1843; Engineer and Inventor; parents: George born Kentucky and Mildred Gains (or Garns) born Kentucky; Widowed; informant: staff member of Eloise Infirmary unreadable. Michigan History Center, on-line records Michiganology.org.
↑ * 1843 birth: He may have been born in Colchester, Ontario, Canada.
↑ 5.05.1 Editors, Biography,"Elijah McCoy, (1844–1929)." A&E Television Networks, The Biography.com website, 2014, update 2020. Note: Second source of inaccurate birth date apparently from Find A Grave. Correction requested.
↑ * 1872 marriage: "Michigan Marriages, 1868-1925," FamilySearch,Elijah Mccoy and Mary E. Delany, 25 Dec 1872; citing Marriage, Ypsilanti, Washtenaw, Michigan, , Citing Secretary of State, Department of Vital Records, Lansing; FHL microfilm 4207572.
Also: Michigan, Marriage Records, 1867-1952, Ancestry.
Name: Elijah Mc Coy
Race: White see note below
Birth Year: abt 1845
Birth Place: Canada West
Marriage Date: 25 Dec 1872
Marriage Place: Ypsilanti, Washtenaw, Michigan, USA
↑ 8.08.1 * 1880 census: "United States Census, 1880," FamilySearch,Kitty L Mccoy in household of Elijah Mccoy, Ionia, Ionia, Michigan, United States; citing enumeration district ED 95, sheet 131D, NARA microfilm publication T9 (Washington, D.C.: National Archives and Records Administration, n.d.), FHL microfilm 1,254,583, accessed 14 August 2017.
Ella Gardner (roomer, dress maker) Female 22 Michigan/NY,NY
↑ * michiganrailroads.com, "Ionia was a crossing of two railroads, the Pere Marquette line... and the Grand Trunk Western..... The Pere Marquette line through town was originally their main route from Detroit northwest....."
Elijah Mc Coy head, 56/m, Mar 1844, md 28yrs, Can/KY/KY, im1863na, engineer
Mary E Mc Coy wife, 54/f, Jan 1846, md 28yrs, 1birth/0living, IN/WV/WV
Andrew O Young nephew, 19/m, May 1881, MO/IN/MO, student
↑ * 1910 census: "United States Census, 1910," FamilySearch,Elijah Mccoy, Detroit Ward 17, Wayne, Michigan, United States; citing enumeration district (ED) ED 262, sheet 8B, family 170, NARA microfilm publication T624 (Washington D.C.: National Archives and Records Administration, 1982), roll 680; FHL microfilm 1,374,693.
↑ * 1929 death: * "Michigan Death Certificates, 1921-1952," FamilySearch,Elijah Mccoy, 10 Oct 1929; citing Nankin, Wayne, Michigan, United States, Division for Vital Records and Health Statistics, Lansing; FHL microfilm 1,973,146
Also: Michigan, Death Records, 1867-1950 Ancestry.
Name: Elijah McCoy
Marital Status: Widowed
Death Age: 86
Birth Date: 27 Mar 1843
Birth Place: Canada
Death Date: 10 Oct 1929
Death Place: Nankin, Wayne, Michigan, USA
File Number: 002335
Father: George McCoy b. KY
Mother: Mildred Ganis b. KY (looks like Gains)
NOTE: inventor is crossed out and engineer written in.
↑ * 2002 findagrave: Elijah McCoy (2 May 1844–10 Oct 1929), Find A Grave: Memorial #6807620, citing Detroit Memorial Park East, Warren, Macomb County, Michigan, USA ; Maintained by Find A Grave. Note: Source of inaccurate birth date, correction requested.
↑"McCoy, George and Mildred", Notable Kentucky African Americans Database; citing Detroit Free Press (newspaper), from "Subscription Database - Access World News (1982-present), n.d., accessed August 18, 2020."