Of what historic importance in titusville, pennsylvania?

As I mentioned elsewhere: Titusville, PA is the location of the first major oil strike in the United States.

In many ways, Titusville marked the beginning of America's obsession with oil and with the business world's interest in oil as a major economic driver.

the answer for 3 is b and the answer for 4 is d

in mcculloch v. maryland (1819) the supreme court ruled that congress had implied powers under the necessary and proper clause of article i, section 8 of the constitution to create the second bank of the united states and that the state of maryland lacked the power to tax the bank.

gibbons v. ogden, (1824), was a landmark decision in which the supreme court of the united states held that the power to regulate interstate commerce, granted to congress by the commerce clause of the united states constitution, encompassed the power to regulate navigation.