After the Civil War, which of the following was an effort by Southern state governments to reimplement some of the constraints that slavery had previously imposed on African Americans?

Lynching refers to the extrajudicial killings, often by mob violence, primarily targeting African Americans during the post-Civil War era. While lynching was a brutal method of enforcing racial terror and dominance, it was not a formal legislative effort like Jim Crow laws. Instead, it represented a violent manifestation of racism rather than a structured legal framework.

The Great Migration refers to the movement of millions of African Americans from the rural South to urban areas in the North and West between 1916 and 1970, seeking better opportunities and escaping racial oppression. While it highlights the response to systemic racism, it does not represent an effort by Southern governments to reimplement constraints on African Americans.

Plessy v. Ferguson was a landmark Supreme Court case in 1896 that upheld the constitutionality of racial segregation under the "separate but equal" doctrine. While it provided a legal basis for Jim Crow laws, it was not itself a legislative effort but rather a judicial endorsement of existing discriminatory practices.