1860 U.S. Census, Baltimore City, Maryland:
Dwelling 379, Household 572
Kopp, Michel [sic], 44, male, day laborer, $0 real estate, $100 personal estate, born in Saxony
Kopp, Barbet, 44, female, born in Saxony
Kopp, Mary, 12, female, born in Maryland, in school
Kopp, Henry, 10, male, born in Maryland
Kopp, Fredrick [sic], 5, male, born in Maryland

1870 U.S. Census, Baltimore City, Maryland:
2nd Ward, written page no. 217, enumerated on 9 August 1870
Dwelling No. 1196, Family No. 1892
Kopp, Michael, 54, wood sawyer, $1800 real estate, $150 personal estate, born in Bavaria
Kopp, Barbara, 54, keeping house, born in Bavaria
Kopp, Henry, 19, segar [sic] maker, born in Maryland
Kopp, Frederick, 15, at home, born in Maryland
Kopp, Charles, 11, at home, born in Maryland

The 1874 Wood’s Baltimore City Directory lists (page 325):
Kopp, Fredrk., cooper, 190 Eastern av
(Frederick Kopps had appeared in earlier directories but not at 190 Eastern av.)

1880 U.S. Census, Baltimore City, Maryland
18th Ward, Enumeration District 169, Sheet 13
360 Sharp Street
Dwelling 1, Family 2
Kopp, Frederick, white, male, 25, married, works “In Guano Factory”, born in Maryland, both parents born in Prussia
Kopp, Annie, white, female, 24, wife, married, keeping house, born in Pennsylvania, father born in Prussia, mother born in Pennsylvania
Kopp, Charles, white, male, 1, son, single, born in Maryland

The 1887 Polk’s Baltimore City Directory lists on page 720:
Kopp Fred, uphlstr, 612 s Dallas 227 [old house number]