Using Pauls uploaded workbook add the states to column A on the Example sheet and run macro
Sub abc()
Dim i As Long
Dim rng As Range, cell As Range
With Worksheets("states")
arr = .Range("a1").CurrentRegion.Value
End With
With Worksheets("Example")
Set rng = .Range("a1", Cells(Rows.Count, "a").End(xlUp))
End With
With CreateObject("scripting.dictionary")
For i = 1 To UBound(arr)
.Item(arr(i, 1)) = arr(i, 2)
Next
For Each cell In rng
If .exists(cell.Value) Then
cell.Offset(, 1) = .Item(cell.Value)
Else
cell.Offset(, 1) = "Not Found"
End If
Next
End With
End Sub
See attached workbook: StatesRegions (1).xlsm