As early as 1882, Dennis and his brother Michael ran a saloon called Vaughn Brothers at 1 East 3rd in Kansas City with the same address as their residence. There was also a grocer named Andrew Vaughn at 5 E. 3rd, perhaps another brother or father. In 1883, Dennis lists his address as 3 E. 3rd, but there is a 2nd Dennis Vaughan living in Wyandotte, Kansas who is a foreman for the K.C. St. J. and C.B. Railroad. From 1884 to 1889-90, there is no Dennis Vaughn in Kansas City, Missouri, only the Dennis who is a railroad foreman in Kansas City, Kansas. I found the Kansas-side Dennis in the 1880 census in Wyandotte, Kansas \footnote{Sup. Dist. 1, E.D. 193, p. 29}, and he must definitely be a second, different Dennis Vaughn because his wife and children are completely different. That Dennis' wife is named Elizabeth Sally , age 24 in 1880, born in NY. That Dennis worked at a RR Depot. I guess it is possible that the two Dennis Vaughns are the same person and that this Dennis' wife died shortly after the 1880 census and Dennis married Margaret for his second wife, but there isn't any evidence for that.
In 1890-91, there is a Dennis Vaughn, foreman (no company named) at 2018 Jefferson in KC, Missouri, which is the address where we find the family of Dennis and Margaret after that.
Andrew is a grocer at 5 E. 3rd from 1882-1884, but in 1885, he is a grocer at the corner of Penn and 22nd. In 1886-1888 Andrew has a saloon there at 2203-5 Penn. Andrew died Dec. 25, 1888. This Penn. and 22nd neighborhood is where brother Michael and Dennis both eventually move, too.
Michael continued running the saloon on 3rd street through 1887. By 1889, he is running a saloon at 2203 Penn, residing at 2107 Penn.
In the 1890s, Dennis and Michael ran a saloon called Vaughn and Vaughn at 2205 Pennsylvania Avenue, Kansas City, Missouri. Dennis and Margaret lived at 2018 Jefferson, and Michael lived at 2107 Penn.
Sources for this individual: @S895@ @S891@