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 16, 1939 issue of Newsweek would have to be renewed in 1967. 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 1966, 1967 and 1968 show no renewal entries for this issue. The first issue to have the copyright renewed is Newsweek. Vol. 37, no. 2, Jan. 8, 1951 according to the Copyright Office database (reg. no. RE0000046287).
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 16, 1939 issue of ''Newsweek'' magazine. The issue features Felix Frankfurter on the cover. The issue cost 10 cents. Works copyrighted before 1964 had to have