How was Jefferson's development of "the grid" involved in the expansion/strengthening of the U.S as a nation?

When you refer to "the grid" I assume that you are talking
about Jefferson's idea of land in the "Northwest Territories" up into the townships and
sections, half sections, etcetera.

If so, I think that
there are at least a couple of ways in which this helped strengthen and expand the
US.

First, I think that this helped by bringing order to
these new areas.  It allowed there to be a very well-defined survey in the new areas so
that there would not be fighting over what land belonged to whom.  This allowed settlers
to move in and be confident that they truly owned their claims.  (I should also mention
that the low prices for the land were important in allowing
settlement.)

Second, I think that Jefferson's idea of
dedicating the income from one section per township to education was important.  It
helped to emphasize the idea that public education was important, even in the frontier
areas.