The Executive branch must receive approval from "the Senate" when appointing heads of executive departments, ambassadors, and Federal Court Judges, since this is one of the most important examples of the system of "checks and balances" that exists in the US.
The answer for this is "Compromise of 1850".
The Compromise of 1850 is a set of laws dealing with the issue of slavery. California was admitted as a free state, upsetting the groups in favor of slavery and satisfying those opposing it in the U.S senate. In Addition, California abolished the slave trade by entering the Union as a free (no slavery) state.
After shortly returning to Medina, Muhammad fell sick with an illness, that ultimately caused him to die.
