en.wikipedia.org/wiki/Aunt_Jemima

This article is about the Aunt Jemima brand, but 1888 is the incorporation year of Pearl Milling Company, not the year the Aunt Jemima-branded product began.

Authoritative brand-history sources separate those two dates:

• Pearl Milling Company’s own history timeline lists 1888 as the year Pearl Milling Company was incorporated, and 1889 as the year the pancake mix originated and was later branded “Aunt Jemima.”
• The Smithsonian’s National Museum of American History likewise says “Aunt Jemima began in 1889 in St. Joseph, Missouri.”

So the infobox date should not identify Aunt Jemima as introduced in 1888.

This sentence assigns the precedent-setting Aunt Jemima trademark ruling to 1915, but the well-known Aunt Jemima doctrine comes from the 1917 appellate decision Aunt Jemima Mills Co. v. Rigney & Co., 247 F. 407 (2d Cir. 1917).

A useful distinction is:

• 1915: underlying litigation/evidence may date from that period.
• 1917: the appellate ruling that is cited as the landmark trademark precedent.

CourtListener’s reporter entry lists Aunt Jemima Mills Co. v. Rigney & Co. with a filing/decision date of December 11, 1917 and citation 247 F. 407. Another legal case source also identifies the case as 247 F. 407 (1917).

So if the article is referring to the famous precedent-setting trademark ruling, 1915 is the wrong year.