Assuming the postal cards are unwatermarked, the first one enscribed "WRITE THE ADDRESS..." is a UX5; the second one enscribed "NOTHING BUT THE ADDRESS..." is a UX7. Catalog value as a used postal card is 45 cents and 40 cents respectively.
Now if you find that the first one has a watermark "USPOD" in monogram, that would make it a UX4 and the value rises substantially to $325. Of course, that variety is obviously quite scarce.
As it relates to the "Andrew Jackson" I found in the US Census Records, here's an excerpt. Of course, I have no way of knowing if it's the same Andrew Jackson on your postal cards, as that would require further research since it is a very common name. However, it is interesting that it is the only Andrew Jackson listed in Oshkosh, Wisconsin for the year 1900.
