Without being able to check the perforations and watermarks of the stamps used on that postcard, it would be impossible to identify exactly what stamps were used. The one cent green Washington could likely be US #498 from 1917 but could also be #424 from 1914, or one of a dozen or so other varieties of the same stamp design. The 4 cent brown from the same series could be #503 or #427 or similar. There is a one-cent Franklin in the lower left branch that is probably #331 from 1908 or #374 from 1910, but again without checking perfs and watermark, it would be difficult to know exactly. A nice piece of historical artwork.
You can find some other examples, mostly from China, in this thread here on SCF -
https://goscf.com/t/67005 Also an article with more history and background -
https://www.iias.asia/the-newslette...tive-america