I am involved in the Alexander yDNA project along some others and we have a lot of fun and successes.YDNA testing is a great way to find otherwise unknown Alexander cousins with whom you can then share information and research efforts.
We have about 80 Alexanders tested, and 6 more awaiting results.We are gaining about 1 new member each week and have been since March.We have about 40 different DNA "families".About 2/3 of the 80 members have already found matches and the other 1/3 are still seeking their first match.
Nearly all of our members have contributed their known lineages and those can be found at http://alexanderdna.org/http://alexanderdna.org/ as can other helpful information.
We also have those same lineages in an Excel spreadsheet which makes it easier to search for names, spouse names and locales.
We also have searchable records of non-testers who have corresponded though not yet tested for whatever reason, usually lack of a male Alexander.
The test is easy, just a swab on the inside of the cheek.
We have technical advice on our staff who will answer any and all questions.We can also help with researching if you would like.
I don’t find your Andrew Jackson Alexander on our lineages but our lineages include only direct ancestors and no siblings.So it does not mean your line is not represented.More information might help.A yDNA test will definitely help.