3. How did the Executive Committee assume power in this case, since there is no mention of consulting Congress? What was their reasoning or justification for acting alone? I

Due to acting alone without congress consultation.

Explanation:

The Executive Committee will be assumed power in this case because the Executive Committee acting alone without consulting the congress in this case. The main reason behind acting alone without congress consultation may be there is no need for consultation in this case because this case is clear and can be completed without the interference of the congress. So that's why  Executive Committee did not consult the congress.

the completion of the erie canal spurred the first great westward movement of american settlers, gave access to the rich land and resources west of the appalachians and made new york the preeminent commercial city in the united states.