The baseball cards used on the cover of Tinker to Evers to Chance are from the T205 "Gold Border" set issued by the American Tobacco Company in 1911. They were inserted into the company's 11 brands of cigarette packs, including American Beauty Black, Hindu, Polar Bear, and Sweet Caporals.
The T205 cards, which feature the first-ever facsimile autographs of ball players, are in the Benjamin K. Edwards collection in the Library of Congress. All 2,100 of the many kinds of baseball cards Edwards collected from the years 1887 to 1914 have been archived in high- and low-res digital versions, and anyone can download them for free (public domain) from the LOC web site.
Edwards collected and preserved these baseball cards in albums containing more than 12,000 other cards on many subjects. After his death, Edwards' daughter gave the albums to Carl Sandburg, the poet and Lincoln biographer, who in turn donated them to LOC in 1954.
The illustrations of Tinker, Evers, and Chance were based on a series of portrait photographs of 26 big league ball players — also in the Library of Congress — taken by Paul Thompson of New York in 1910. (See below.) They, too, are digitally archived and remain in the public domain.