The organization called [blank] organized an oil embargo against the united states.

Organization of Petroleum Exporting Countries

Explanation:

The Organization of Petroleum Exporting Countries organized an oil embargo against the United States.

Most people know this as the (OPEC).

b.   jim crow laws were enacted in northern states.

"a government in which power is divided between state and national levels". federalism is a system of government in which entities such and state and province, share power with the national government.