Works copyrighted before 1964 had to have the copyright renewed sometime in the 28th year. If the copyright was not renewed the work is in the public domain. It is best to search 6 months before and after the required year. Some magazines are published the month before the cover date and some registrations may be delayed for a few months.
The January 1948 issue of Esquire would have to be renewed in 1975. Online page scans of the Catalog of Copyright Entries, published by the US Copyright Office can be found here. http://onlinebooks.library.upenn.edu/cce/
The search of the Renewals for Periodicals for 1974, 1975 and 1976 show no renewal entries for this issue. Two Esquire issues in 1948, from vol. 29, January and March and from vol. 30 the October, November and December issues are in Public Domain as their copyright was not renewed.
The copyright on this magazine was not renewed and it is in the public domain.
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={{en|Cover of the January 1948 (vol. 29 issue 1) issue of Esquire magazine. Works copyrighted before 1964 had to have the copyright renewed sometime in the 28th year. If the copyright was not renewed