With the "mixed government" concept in the u. s. constitution, the founding fathers attempted to capture the benefits of an oligarchy in:

Here is the answer that would complete the statement above. With the "mixed government" concept in the U.S. Constitution, the Founding Fathers attempted to capture the benefits of an oligarchy in: dispersing power between the federal government and the states. Hope this helps.

Primary sources are usually  more accurate and are written by someone who experienced it or witnessed it. secondary sources are those who heard of it after the fact that can lose details and or twist the event in a light that benefits them.