The DAR (Daughters of the American Revolution) Library has created an online searchable database, The DAR Genealogical Research System.
To access the system, go to the link above, then select "Click Image to Open GRS." This takes you to a Welcome page and you will then select "Enter Site." You will then see the "Ancestor Database Overview" where you will, once again, select "Enter" (I agree, there are a few too many steps here, they could have done a better job of streamlining this). Now you will arrive at the Ancestor Search page. The Tabs at the top will take you to other Search pages, such as, Descendants Database Search.
The DAR chapters were formed as early as 1890, and the National Society became incorporated in 1896. Membership is open to all women who can prove a lineal bloodline descent from an ancestor who participated in the movement for United States Independence. Since inception, the DAR has been collecting thousands of applications, and genealogical researchers have sought them out as aids in conducting their research. With the DAR GRS, anyone can now have quick access to thousands of lineages, information that previously was only available (with less detail) in numerous volumes of books published by the DAR.
An example: Starting from the Ancestor Search page (as accessed above) type in for Ancestor Last Name, "Brewer", and then for Ancestor First Name, "John" (no quotes). Hitting the Search button brings us to a page with nine different men named John Brewer, who claimed as ancestors by various descendants seeking admission to the DAR. The "See Ancestor Record" button will take you to a new page with the ancestor's service, a tab with their spouse or spouses, and then a tab with Associated Applications and Supplements. In this section, under "Docs" there are small boxes with the letter "D". Clicking on each will take you to the lineage as submitted by each applicant.
This is a nice tool to have. It certainly makes a tremendous amount of information available to all, conveniently, and at no cost (complete records, if needed, have to be purchased). But now that I have brought this up, I do have to add a caveat, which is, DAR lineage applications contain a terrific number of errors. They should not be considered as proof of a lineage in and of themselves. Additional evidence for the stated lineages should be located.
There may also be errors in the crediting of service to a specific ancestor. Take for example, the case of John Brewer of Scioto Co., Ohio, who would be the seventh John Brewer down on the page opened up by following the above instructions. The service shown for him is with the Frontier Rangers, under Capt. John Leech. That a man named John Brewer served under Capt. Leech is certain (see Pennsylvania Archives, 3rd Series, Vol. 23, pages 284 and 316, as cited on this page). However, there likely were a number of men named John Brewer who were living in the area of south central and western Pennsylvania at the time of the Revolution. Any one of them could have been the John Brewer who served under Capt. Leech, and no information or records survive from that time that will tell us, with certainty, just exactly who the John Brewer who served, was. The claim that John Brewer of Scioto Co., Ohio was the John Brewer who served under Capt. Leech, cannot be proved, despite the apparent acceptance of this service which allowed some descendants to gain admission to the DAR.
I use the DAR lineages as a starting point. I note the lineage, and then I see if I can find supporting documents for each generation. If the lineage is correct, then you should be able to find the evidence needed to support the claims. If you can't, well then you might want to question the applicant's claim. It is important to take this step, do not simply accept the lineages at face value.