Why would a researcher use a secondary source instead of a primary source when analyzing historical event

Hich explains why the constitution gave congress the power to create a system of federal courts? the constitution wanted congress to share power with the judicial branch. the constitution anticipated the need for courts lower than the supreme court. the constitution wanted congress to share power with the appellate courts. the constitution anticipated the need for courts equal to the supreme court.

Other in the u.s. supreme court, all federal courts were established bya. the constitutionb. congressc. presidential executive orderd. the states

In this diary only in researching sidney montz or can it be used to research broader subjects