You may be surprised to find a link to the ACGS Yearbooks, given that I have confessed my lack of belief in Alexander Magruder’s Clan Gregor origins; but the ACGS was founded by Magruders and Magruders still make up a large portion of its membership, so it follows that the yearbooks are full of information by and about Magruders.
Unlike recent yearbooks, which focus on activities in the present, the early yearbooks were full of historical articles, family histories, memorials to individual ancestors, transcriptions of wills, and the like. All are available as PDFs from the ACGS Library, now in the care of Special Collections at the Langsdale Library of the University of Baltimore.
Use these articles with caution! The authors were not professional historians or genealogists. Some were careful and reasonably skilled, others appallingly bad on both counts, and nearly all the articles contain errors of omission if not outright wrong “facts.” In these old publications, legend and pure speculation enjoy equal status with research. For most, the goal was celebration of a heritage, not its verification.
Check the evidence, corroborate, and correlate. Look for original records and for multiple sources.
Be particularly cautious when you notice that the writers cite each other as authorities. Most of the historical articles were penned by three or four men, who are content to rely on each other without risking any further inquiry. These guys were friends and colleagues, working together to establish a historical grounding for the ACGS. You can’t blame them for accepting each other’s word–but you don’t have to.
For example, you may be excited to see that both Mr. A and Mr. B make the same claim about such-and-such…then find, on closer scrutiny, that Mr. B’s authority is Mr. A. So all you have, after all, in Mr. A’s assertion, for which he offers no evidence.
Phrases like “it is traditional” also should set off alarm bells. Most assertions that follow that phrase will turn out to have no basis in the historical record, and some will turn out to have no basis in oral history either. Such phrases can be used to cloak speculation in an air of authority.
Ask where the “tradition” comes from and who has handed it down.
The prime example for us, of course, is the “tradition” that Magruders/McGruders were part of Clan Gregor, which has flourished among American Magruders for around 200 years but is unknown to McGruders in Scotland. The idea was introduced to Scottish MacGregors in the 20th century and many have accepted it, but neither the historical record nor DNA has thus far supported it. Alas!
So where did this belief come from? When, where, and why did 19th c. Magruders adopt this belief? That’s worth finding out.
Don’t be intimidated by sources that sound antique and grand. Try a web search to find out the exact nature of these old books. Who wrote them? Who published them? For what audience and for what gain? Look for critical views and academic assessments. Dare to read what modern historians have to say on the same subjects.
For example, Sir Robert Douglas’ Baronage of Scotland (1798) was taken as authoritative by 19th and early 20th c. researchers and enthusiasts. Now available on line, it is offered by its editors as a sociological document–a snapshot of the beliefs of its day–and, at best, only a starting point for research. The Clan Gregor entry, often cited in support of the most grandiose claims about the clan chiefs’ genealogy, has been described by historian Martin MacGregor as “a work of sustained fiction.”
In short, be skeptical of claims that are not backed up by citations of sources. Be proactive in following up on those sources. Compare and correlate different sources, making sure they are independent of each other–that is, not all relying on the same prior source. On some questions, you may never have a hard and fast proven fact, but multiple independent sources that suggest the same conclusion will give you far more certainty than one self-confident writer who offers no evidence for his or her claims.
And above all, enjoy the hunt!