Morton Salt started out as a Chicago sales agency in 1848, called Richmond & Company, Agents for Onondaga Salt. The discovery of gold in California in 1849 created a huge demand for salt as fortune-seekers made the long journey west. In 1889 Joy Morton (whose father served as secretary of agriculture under Grover Cleveland and invented Arbor Day) acquired a major interest in the company and renamed it Joy Morton & Company. In 1910, the firm was finally renamed the Morton Salt Company.
Morton Salt began adding magnesium carbonate as an anti-caking agent to its salt in 1911. The Morton Salt Umbrella Girl was born in 1914, along with the slogan, "When it rains it pours."
...Get it? BECAUSE WHEN IT RAINS AND IT'S HUMID OUT THE SALT STILL POURS!
This blew my mind. Anyway, 1924 brought iodized salt, and then here is a progression of the Morton Salt Umbrella Girl over the decades:
Isn't she adorable? She reminds me of the Coppertone girl, but I feel less awkward.