The supreme court case marbury v. madison happened because

Marbury v. Madison, 5 U.S. (1 Cranch) 137 (1803), was a U.S. Supreme Court case that established the principle of judicial review in the United States, meaning that American courts have the power to strike down laws, statutes, and some government actions that contravene the U.S. Constitution.

Marbury v. Madison - Wikipedia

https://en.wikipedia.org/wiki/Marbury_v._Madison

might be agreeing to participate ethically with other european nations in the slave trade

or notifying other european nations when taking possession   of african territories

the answer is: must pay taxes on profits

since it is considered as a part of your income, profits from investments is eligible for tax payment.

the tax from your investment could be influenced by how long you decided to sell it. united states promotes keeping your investment for long term period. so, the tax rate for investments that you sell in less than one year is typically higher compared to investments that you sell in more than one year period.