Final answer:
Option (a), The period after the American Revolution experienced economic difficulties and political instability. The weak central government under the Articles of Confederation posed challenges, and increased political participation emerged from the middle classes amidst a landscape of cultural diversity.
Step-by-step explanation:
The similarities between the newly formed United States experienced after the American Revolution are best described as economic collapse and political chaos. After gaining independence, the United States faced numerous challenges such as waging war, collecting taxes, and signing treaties due to the initially weak central government under the Articles of Confederation.
The political landscape was dominated by conflicts between those preferring a federal-style government and those favoring a unitary-style government, leading to the adoption of the Constitution in 1789 to address these issues.
The social structure remained multi-layered, with increasing participation from the middle classes in politics and military service. Despite growth in nationalism during the war, each state still saw itself as a separate entity, and there was no immediate creation of a strong centralized government nor was there instant social unity. Cultural diversity and questions of rights for various social groups also characterized the post-Revolution period.