How did the system of checks and balances in the federal government help to limit the concentration of power?

From the very inception of the federal government, the country's founders were concerned about the possible abuses of power that could take place if power were concentrated in the hands of a few individuals. In order two counter this threat of tyranny, the government was divided into three main branches: legislative, executive, and judicial. While each branch has very different responsibilities and functions, it also has certain abilities to limit the power of the other branches.
The modern idea of checks and balances was first articulated by the French philosopher Baron de Montesquieu in the eighteenth century. He argued that the ability of one part of the government to place checks and balances over another part while exercising its own unique functions would protect the will of the people, prevent fraud, and limit mistakes. While this system of government might not be as efficient or expeditious as a single ruler, it would eliminate what Montesquieu called "arbitrary control."
The United States Constitution lays out the function of the federal government and borrows heavily from Montesquieu's ideas of the separation of powers and checks and balances. For example, Congress (legislative branch) can pass a law, but the president (executive branch) can veto the law. In turn, Congress has the ability to overturn a presidential veto. The president nominates judges (which are in the judicial branch), but these judges must be approved by Congress. Indeed, the legislative branch, namely the Senate, must approve most presidential nominations. It can also impeach judges appointed by the president and even the president too. The judicial branch can check the power of the two other branches by declaring laws or executive actions to be unconstitutional.
As a result of all these checks and balances, the process of creating and implementing laws can be cumbersome and move slowly. This was done by deliberate design. Federal action can only occur if the majority of government is in agreement. No president, judge, or congressional body can act independently. Throughout the history of the United States there have been many presidential vetoes, many of which were then overridden. The courts have found many laws and executive actions to be unconstitutional and presidential nominations have been denied.
Because of this system, power in the federal government is spread around the different branches rather than being concentrated in a single source with the ability to abuse it.