Alden, Aldin Surnames

English: from a Middle English personal name. This is either Aldan, a variant of Healfdane (see Haldane), or Aldine, Old English Ealdwine, literally ‘old friend’, but probably to be interpreted as ‘friend of the past’.
Norwegian: habitational name from a farmstead in western Norway, so named because of its situation below a high mountain.

Dictionary of American Family Names, Oxford University Press, ISBN 0-19-508137-4