Which of the following statements about the Reconstruction era in United States history is false?

Introduction / Context:
The Reconstruction era followed the American Civil War and aimed to rebuild the Southern states and integrate formerly enslaved people into political and social life. Several important constitutional amendments were passed during this period. This question asks you to identify which statement about Reconstruction is false, which requires a basic understanding of how constitutional law and actual state practice often differed.

Given Data / Assumptions:

• The topic is the Reconstruction era after the American Civil War.
• The Thirteenth and Fourteenth Amendments are specifically mentioned.
• The options contrast changes in law with actual practice in the states.

Concept / Approach:
To answer, you should know the content of the Thirteenth and Fourteenth Amendments and the reality of life for African Americans in the post war South. The Thirteenth Amendment abolished slavery, and the Fourteenth Amendment granted citizenship and equal protection under law. However, Southern states often used discriminatory laws and customs to undermine these amendments. Therefore the false statement will be the one that incorrectly claims that state laws and customs fully supported the new rights.

Step by Step Solution:
Step 1: Recall that the Thirteenth Amendment formally ended slavery throughout the United States, so that statement is true. Step 2: The Fourteenth Amendment granted citizenship to all persons born or naturalized in the United States, including African Americans, so that statement is also true. Step 3: Federal law and constitutional amendments did abolish slavery and attempt to protect civil rights, which matches option mentioning federal law changes. Step 4: However state laws and customs in many Southern states created Black Codes and later Jim Crow laws that restricted African American rights. Step 5: Therefore the statement that state laws and customs upheld the amendments in full is false.

Verification / Alternative check:
History accounts describe how, despite the new amendments, African Americans faced segregation, disenfranchisement, and violence. Supreme Court decisions of the late nineteenth century upheld segregated facilities and weakened federal enforcement. This shows that state practice often violated the spirit of the amendments. Thus any claim that state laws and customs fully upheld the constitutional changes cannot be correct.

Why Other Options Are Wrong:
The Fourteenth Amendment made African Americans citizens of the United States: This is historically accurate, so it is not the false statement.
The Thirteenth Amendment outlawed slavery in all American states: This is correct and considered a landmark change in United States history.
Federal law was changed to abolish slavery in states where it still existed: This correctly reflects the effect of the Thirteenth Amendment and related legislation and is therefore true.

Common Pitfalls:
Some learners mistakenly assume that because conditions were poor for African Americans, the amendments must not have existed or must be the false statements. In reality, the amendments were real, but enforcement was weak and state level resistance was strong. The trick in this question is to distinguish between constitutional law and everyday practice. When a statement claims that state laws and customs fully upheld equal rights, it ignores the well documented history of discrimination.

Final Answer:
The false statement is that state laws and customs fully upheld the new constitutional amendments.