Peck and Snyders from 1868 are typically considered the first baseball card. Yet the concept of the first card varies by collector.
http://www.oldcardboard.com/n/peck-s...?cardsetID=675
There is an 1886 Old Judge that would predate the 1887 yet are even harder to find.
http://www.oldcardboard.com/n/n167/n...?cardsetID=656
I do not have either for sale and most times you are going to have to wait for one to show up in a large auction house.