Meaning of "Well regulated"

[aslinged]

The power of the sword, say the minority..., is in the hands of Congress. My friends and countrymen, it is not so, for The powers of the sword are in the hands of the yeomanry of America from sixteen to sixty. The militia of these free commonwealths, entitled and accustomed to their arms, when compared with any possible army, must be tremendous and irresistible. Who are the militia? Are they not ourselves? Is it feared, then, that we shall turn our arms each man against his own bosom. Congress has no power to disarm the militia. Their swords and every terrible implement of the soldier are the birthright of Americans. The unlimited power of the sword is not in the hands of either the federal or state governments but where, I trust in God, it will always remain, in the hands of the people.

Tench Coxe, The Pennsylvania Gazette, Feb. 20, 1788.