purely speculative identification, from left:

William A. Flood

Mary A. Fox

unknown

unknown

late 1800's

some sort of Brooklyn club outting

mid 1920's

send message if you can identify anyone in picture

marked on back, "Captain's Dinner, Rivoli Resturant"

heavy-set fellow in black suit, center, 2nd row from bottom is Francis A. Nolan Commisioner of Public Works, City of New York

1940's

here's a advertisement found in the 1884 Brooklyn Directory