Detailed Instructions: Answer the question from the given passage. Your answer should be directly extracted from the passage, and it should be a single entity, name, or number, not a sentence.
Q: Passage: France took control of Algeria in 1830 but began in earnest to rebuild its worldwide empire after 1850, concentrating chiefly in North and West Africa, as well as South-East Asia, with other conquests in Central and East Africa, as well as the South Pacific. Republicans, at first hostile to empire, only became supportive when Germany started to build her own colonial empire. As it developed, the new empire took on roles of trade with France, supplying raw materials and purchasing manufactured items, as well as lending prestige to the motherland and spreading French civilization and language as well as Catholicism. It also provided crucial manpower in both World Wars. Question: When did France begin in earnest to rebuild its global empire?
A:
after 1850