Early-vesting rule

it has long been a settled rule of construction in the courts of England and America that estates, legal or equitable, given by will, should always be regarded as vesting immediately, unless the testator has by very clear words manifested an intention that they should be contingent upon a future event. ... Words directing land to be conveyed to or divided among remaindermen after the termination of a particular estate are always presumed, unless clearly controlled by other provisions of the will, to relate to the beginning of enjoyment by the remaindermen, and not to the vesting of the title in them.