Onllwyn was involved in several 20th-century coal mining strikes which brought the town notoriety. The political, labour and cultural connections between Onllwyn and the American coal mining region known as Appalachia grew into an in-person cultural exchange in the 1970s. Musical acts were performed at Onllwyn Miners' Welfare Hall in 1976, including a performance by The Strange Creek Singers featuring American musicians Hazel Dickens, Alice Gerrard, Mike Seeger, Tracy Schwartz, and Lamar Grier. The exchange was facilitated and filmed by Helen Lewis and John Gaventa.