Red text on a white background.
This may be a button from the 1937 American Association of Nurserymen convention in Chicago.
The American Association of Nurserymen was founded in 1876 as a way to bring the community of nurserymen across the country together and offer gardening advice to the public. It is now known as the American Nursery & Landscape Association.
Sources: Conventions for Chicago: Association of commerce signs up many gatherings for 1937. (1936). New York Times, pp. 51.
AmericanHort (2014). Where we started. AmericanHort: The consolidation of ANLA and OFA.