Hi Dallas,

I've never done this but I would start using the GetVersionCollection method of SharePoints ootb Lists.asmx web service.

As parameters you have to provide the List ID, Item ID and Field Name. As a result you will receive something like this:

<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">

  <soap:Body>

    <GetVersionCollectionResponse xmlns="http://schemas.microsoft.com/sharepoint/soap/">

      <GetVersionCollectionResult>

        <Versions>

          <Version Title="ccc" Modified="2016-05-03T08:43:41Z" Editor="1;#Johnny Developer,#i:0#.w|devdeveloper,#developer@sp.dev,#,#Johnny Developer" />

          <Version Title="bbb" Modified="2016-05-03T08:43:22Z" Editor="1;#Johnny Developer,#i:0#.w|devdeveloper,#developer@sp.dev,#,#Johnny Developer" />

          <Version Title="aaa" Modified="2016-03-22T12:48:57Z" Editor="1;#Johnny Developer,#i:0#.w|devdeveloper,#developer@sp.dev,#,#Johnny Developer" />

        </Versions>

      </GetVersionCollectionResult>

    </GetVersionCollectionResponse>

  </soap:Body>

</soap:Envelope>

You would probably have to extract the relevant information using XPath and/or a Regex but it should provide all the information you need.

Cheers

Philipp