Great Kinnick photo, Matt! Love it.
Prior to the NFL there were many informal pro leagues out there. Several of them had teams that joined the NFL in 1920. One of these leagues was the New York Pro Football League (NYPFL) that was active in New York during the 1910s.
Here is a photo of the Lancaster Pros / Malleables from around 1911 or so.
The Lancaster Pros won the NYPFL title two consecutive years in 1913-1914. However, the most significant thing about this team is that one of the very early African-American pro football players, Henry McDonald, must have played for them occasionally as he is in this photo.
Henry McDonald was officially a member of the Rochester Jeffersons but was known to play for other teams when possible to make more $$$$. Later in life he said he only had one racial incident while playing pro football and it was when the Jeffersons were playing the Canton Bulldogs of the Ohio League. Greasy Neale threw him out of bounds and reportedly said "Black is black and white is white and where I come from the two don't mix." McDonald, who was a boxer, confronted Neale and was ready to fight when Jim Thorpe stepped in and told Neale that they were there to play football and to lay off. McDonald said nobody else from Canton bothered him after that.
The Rochester Jeffersons joined the NFL when it started up but by then McDonald had retired.
jeff