What significant feature of the Constitution of 1861 is explicitly mentioned?

The Constitution of 1861 includes a significant feature that is focused on the foundational aspects of the government and legal framework established during that time. Judicial review was an important principle that emerged as a means for the judiciary to interpret the Constitution and ensure that laws and actions of the executive and legislative branches adhere to constitutional mandates. This principle allows courts to assess the constitutionality of laws and executive actions, thereby upholding the rule of law and serving as a check on governmental power.

While the other options touch on relevant topics concerning rights and governance, the specific emphasis on judicial review as a significant feature underscores the evolving understanding of the judiciary's role in American governance at that time. This feature laid the groundwork for future legal principles and practices regarding the interpretation of laws and the balance of power among the branches of government.