Jefferson on subsidiarity

Subsidiarity is the principle which states that matters ought to be handled by the smallest (or, the lowest) competent authority.

Here's Jefferson in his autobiography as cited in The Founders' Constitution:

But it is not by the consolidation, or concentration of powers, but by their distribution, that good government is effected. Were not this great country already divided into states, that division must be made, that each might do for itself what concerns itself directly, and what it can so much better do than a distant authority. Every state again is divided into counties, each to take care of what lies within it's local bounds; each county again into townships or wards, to manage minuter details; and every ward into farms, to be governed each by it's individual proprietor. Were we directed from Washington when to sow, & when to reap, we should soon want bread. It is by this partition of cares, descending in gradation from general to particular, that the mass of human affairs may be best managed for the good and prosperity of all.

The sentence "Were we directed from Washington..." is illustrated by the experience of the Pilgrims their first few years here. They set up a farming system such that all food was grown in common on common land. They starved. Then William Bradford, the governor of Plymouth Colony, gave each family their own land to farm, which "made all hands very industrious, so as much more corn was planted than otherwise would have been by any means the Governor or any other could use, and saved him a great deal of trouble, and gave far better content". See the journal of William Bradford, excerpted at The Founders' Constitution.

Intro to the Constitution

If you've forgotten your basic Constitutional principles, here's an introduction from a reliable source: James McClellan: Liberty, Order, and Justice: An Introduction to the Constitutional Principles of American Government (1989).

That's at the Online Liberty Library at the Liberty Fund; here's an obituary of James McClellan, who died in 2005.