Flat caps were very common for North American and European men and boys of all classes during the early 20th century and were almost universal during the 1910s-20s, particularly among the working "lower" classes. A great many photographs of the period show these caps worn not only by newsboys, but by dockworkers, high steel workers, shipwrights, costermongers, farmers, beggars, bandits, artisans, and tradesmen of many types. This is also well attested in novels and films of this period and just after. Eight-piece style caps are essentially an offshoot of a Scottish tam o' shanter.
