Newspaper ad for Bayer Aspirin from the USA, dated 1918. The USA was at war with Germany, the aspirin patent had expired and Bayer would not lose the right to use the trademark yet (it would in 1919). Also note the "patriotic" saying to promote Liberty Bond sales.
Bayer
New-York tribune. (New York [N.Y.]), 14 April 1918. Chronicling America: Historic American Newspapers. Lib. of Congress. &lt;<a rel="nofollow" class="external free" href="http://chroniclingamerica.loc.gov/lccn/sn83030214/1918-04-14/ed-1/seq-59/">http://chroniclingamerica.loc.gov/lccn/sn83030214/1918-04-14/ed-1/seq-59/</a>&gt;