Answer:
d q alam ang sagot eh sorryyyyyyyyyyyy
What do mean be more Specific
C. Buffalo.
The Erie Canal connected Albany on the Hudson with Buffalo :)
The federal legislature or congress can repeal the state laws under the necessary and proper clause in order to impose federal laws necessary to provide general welfare and common defense of the nation because they have the authority to do so. This authority was given to them because the people believed that the congress would decide for the common good.
Moreover, only the federal legislature has the right to contract debts, lay taxes and if they believed that a state law may prevent the collection of a federal tax, then they can repeal state laws making sure that it is for the benefit of the United States.
Answer: Slavery became a national issue because it split the country into two groups due to each state's beliefs on slavery. To be more specific, the Southern states were pro-slavery, and the Northern states were anti-slavery. This caused a civil war between the two groups, which made Abraham Lincoln, the president at the time, abolish slavery.
I hope this helped!! :)