Sorry, after taking the shot I realized it's not as crisp as I'd like, but between the photo and the information I'll type here, you'll have everything:
http://www.dminet.com/ignatz/WhiteHo..._Tax_Stamp.jpg
The tax stamp is slightly obscured, since it split at some point along the line of the underlying White Horse front label wrap-around. It says:
State of Illinois
Alcoholic Liquor Revenue (around the State Seal)
24974 (could be 214974, if that's a '1' under the split)
1/5 Gallon Series N (in circle in the bottom half of the state outline
TAX PAID AT THE RATE OF $1.00 PER GALLON
Note that there had been a US Tax Stamp across the top of the bottle and under the White Horse neck label, but over the decades all but the very bottom has disappeared; all you can make out on one piece is "4/5 Quart".
Hope this helps!