Based on the article, why did the Great Migration end in the 1970s?

As a result, approximately 1.4 million black southerners moved north in the 1940s, f By the late 1970s, as deindustrialization and the  the Great Migration came to an end.

answer:

the majority of cambodians living today were born after the khmer rouge was ousted in 1979 and some who survived can forget how bad it was. when khmer rouge forces seized phnom penh on april 17, 1975, the couple was living with eight of their children in a rural town called kampong chhnang.

explanation:

europe would not recognize the confederacy as an independent nation.