This vintage photo postcard depicts the memorial plaque to the Mayflower, the ship which carried the first English Puritans to America, with a second image of a group of people standing around the plaque itself. There is a message on the back from "R.J. Dowling" to "F.J.C. Wakefield Esq", with a few comments on the Puritans that left ("...in the name of - to be courteous let me say - religion..."). It also has some pencilled in comments about the Mayflower itself.
There are two franking marks with the year rather faint on both, but they appear to read "20 Sep 19", which combined with the stamp depicting King George V would suggest a year of 1919 for when it was sent.