From left to right are:

• Robert Walton Moore (1859-1941), Assistant Secretary of State
• Admiral William Harrison Standley (1872-1963)
• Dr. Hugo Eckener (1868-1964)
• Commander Charles Emery Rosendahl (1892-1977), chief of the Lakehurst Naval station

• A renewal search in artwork and periodicals was done for the years 1963 and 1964. There were no renewals for Associated Press or for the Ithaca Journal. There's no evidence of copyright continuing to be claimed on this material.

This work is in the public domain because it was published in the United States between 1929 and 1963, and although there may or may not have been a copyright notice, the copyright was not renewed. For further explanation, see Commons:Hirtle chart and the copyright renewal logs. 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. العربية ∙ Deutsch ∙ English ∙ español ∙ français ∙ galego ∙ italiano ∙ 日本語 ∙ 한국어 ∙ македонски ∙ português ∙ português do Brasil ∙ русский ∙ sicilianu ∙ slovenščina ∙ українська ∙ 简体中文 ∙ 繁體中文 ∙ +/−