A renewal search was done at copyright.gov for Maxwell House and General Foods. There were no listings for Maxwell House. The only renewal for General Foods was for a cookbook published in 1959. There's no evidence of continuing copyright for the book.
Note that it may still be copyrighted in jurisdictions that do not apply the rule of the shorter term for US works (depending on the date of the author's death), such as Canada (70 years p.m.a.), Mainland China (50 years p.m.a., not Hong Kong or Macao), Germany (70 years p.m.a.), Mexico (100 years p.m.a.), Switzerland (70 years p.m.a.), and other countries with individual treaties.
{{Information |Description=Front cover of a 1955 Maxwell House Haggadah. |Source=[http://web.archive.org/web/20160421005939/http://www.ebay.com/itm/Maxwell-House-1955-Vintage-Haggadah-Judaica-/141890443582?hash=item210954593e%3Ag%3AfcgAAOSwpzdWq6Pl&nma...
File history
Click on a date/time to view the file as it appeared at that time.