In southern france, the gap is an ancient routeway leading from the atlantic to the mediterranean lands.

In southern France, the Carcassonne gap is an ancient routeway leading from the Atlantic to the Mediterranean lands. Carcassonne is located southeast of Toulouse (about 90km) in the middle of the Massif Central and Pyrenees in France. It is situated in the intersection of the two main routes of traffic: the route that goes from the Massif Central to Spain and the route going from the Atlantic to the Mediterranean lands. 

in the 1800s, chinese workers migrated to the united states, first to work in the gold mines, but also to take agricultural jobs, and factory work, especially in the garment industry. chinese immigrants were particularly instrumental in building railroads in the american west, and as chinese laborers grew successful in the united states, a number of them became entrepreneurs in their own right. as the numbers of chinese laborers increased, so did the strength of anti-chinese sentiment among other workers in the american economy. this finally resulted in legislation that aimed to limit future immigration of chinese workers to the united states, and threatened to sour diplomatic relations between the united states and china.