This work is in the public domain in the United States because it is a work prepared by an officer or employee of the United States Government as part of that person’s official duties under the terms of Title 17, Chapter 1, Section 105 of the US Code. Note: This only applies to original works of the Federal Government and not to the work of any individual U.S. state, territory, commonwealth, county, municipality, or any other subdivision. This template also does not apply to postage stamp designs published by the United States Postal Service since 1978. (See § 313.6(C)(1) of Compendium of U.S. Copyright Office Practices). It also does not apply to certain US coins; see The US Mint Terms of Use.
This file has been identified as being free of known restrictions under copyright law, including all related and neighboring rights.

https://creativecommons.org/publicdomain/mark/1.0/PDMCreative Commons Public Domain Mark 1.0falsefalse

...However, any copyright held by ACME that is still current would now be owned by CORBIS. In an attempt to determine if ACME registered any copyrights and if those copyrights were renewed, Specialists in the Prints and Photographs Division of the Library of Congress searched the Copyright Office files. It was found that only a few images were registered for copyright and those copyrights were not renewed. However, the Library’s legal office has advised the Division that photographs published with proper copyright notices between 1923-1963 may be protected if properly renewed, while works published after 1963 and unpublished photographs in the collection may be protected even if they were not registered with the Copyright Office. Additionally, researchers should be advised that determining the copyright status of photographs can be problematic because of the lack of pertinent information, and researchers often have to make calculated risk decisions concerning the appropriate use of an image when its copyright status is unknown or ambiguous.

— https://www.loc.gov/rr/print/res/220_acme.html