During which historical period did the British and French forces fight alongside irregular Colonialists?

The correct answer relates to the historical context of the Seven Years' War, which is often noted in North America as the French and Indian War. This conflict lasted from 1754 to 1763 and involved British and French colonial powers as well as various Indigenous allies and irregular Colonialist forces.

During this period, the British and their Colonial allies fought against the French forces, who were supported by various Indigenous nations. The collaboration between the British, their Colonial forces, and Indigenous groups was vital for military operations during this conflict, emphasizing the complex relationships and alliances that existed. This period marked significant developments in territorial control in North America and set the stage for future conflicts, including the American Revolutionary War.

The other historical periods mentioned do not align with the context of British and French forces collaborating alongside irregular Colonialists.