Here are some of my favorite reliable food history resources for primary sources: 

• New York Public Library Digital Menu Archive

• Los Angeles Public Library Digital Menu Archive

• What America Ate Digital Archive

• Food Additives History at the Science History Institute

• USDA Resources for Homemakers, 1926-1946

• Culinary Institute of America Digital Menu Archive

• California Historical Society Digital Menu Archive

• J. Lilek’s collection of antique restaurant postcards

• Hathi Trust’s Food Studies collection

• Michigan State University’s Feeding America Collection

• Hagley Digital Archive DuPont Pamphlets

• DPLA Primary Source Set on the History of Food Stamps in America