It is the opposite of the feudal system as it supposes no obligation to another (ie. a lord).
When the USA broke away from England, the unfeterred use and charging of land by the owner was a primary objective.
"All lands within the state are declared to be allodial, and feudal tenures are prohibited. On this point counsel contended, first, that one of the principal elements of feudal tenures was, that the feudatory could not independently alien or dispose of his fee; and secondly, that the term allodial describes free and absolute ownership, ... independent ownership, in like manner as personal property is held; the entire right and dominion; that it applies to lands held of no superior to whom the owner owes homage or fealty or military service, and describes an estate subservient to the purposes of commerce, and alienable at the will of the owner; the most ample and perfect interest which can be owned in land."Barker v Dayton 28 Wisconsin 367 (1871)