Moving the US to a war footing before and during the Second World War was probably the largest industrial shift in American history. In rural Wisconsin, the largest munition factory in the world sprung up as if out of nowhere, just one of many military facilities the size of cities built to help meet the needs of a global war.
The Reconquista, or Christian reconquest of Iberia, took nearly 800 years. The fighting did not come without great attempts by Muslim powers across the strait trying to reestablish their presence in mainland Europe. The last gasp of that effort came in the 1330s, when the powerful Marinid sultanate of what is modern Morocco invaded in an attempt to reverse Christian gains and secure the perilous position of the Sultanate of Granada.