Final answer:
The word 'upbraid' in the context of 'The Constitution of the Iroquois Nations' means to scold or reprimand someone. In this context, future Americans admired and praised the Iroquois Confederacy's constitution.
Step-by-step explanation:
The word 'upbraid' as it is used in the context of 'The Constitution of the Iroquois Nations' means to scold or reprimand someone for their actions or behavior. In the text, the word upbraid is used to describe the reaction of future Americans, such as Washington and Franklin, to the concepts of the Iroquois Confederacy's constitution.
These American leaders greatly admired the ideas of checks and balances and separation of power that were incorporated into the Iroquois Confederacy's constitution.
Therefore, in this context, upbraid suggests that future Americans praised or commended the Iroquois for their constitution.