In short, if you marry a LPR, you have to wait for a visa # and overstays aren't forgiven. If you marry a USC, overstays are forgiven and as an immediate relative a visa # is automatic and you can do a i-130 along with an adjustment of status (i-485).
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Those who would give up Essential Liberty to purchase a little Temporary Safety, deserve neither Liberty nor Safety.
-Benjamin Frankln