That's great to hear, but the definitive list of currently recognized charities is Publication 78 of the IRS, which lists every charity recognized by the IRS. It is updated frequently and is now only available online:
http://www.irs.gov/app/pub-78/ That publication lists all US charities to which deductible charitable contributions can be made.
I searched for every charity beginning with the word "Capital" in hopes of finding it and could not. So, unless it is listed under another name, or someone else with more time than I have right now can poke around and find it, chgpa does not
now appear to have that status.
A phone call to the IRS from one of the current officers could ask the question: "What do their records show as the form of exempt organization of chgpa (give its legal name), taxpayer ID number 12-3456789 (whatever the correct one is)" They will tell you what they have on record. The answer should be something like: "501c3" or "501c7", etc. The IRS will willingly talk to officers of an organization but not just to anyone who has a question about an organization. Hence, the need for an officer to make the call.
Despite popular misconception, the IRS doesn't (usually) bite, so I suggest you give that a try. If, indeed, it has fallen off of the list, it might be worthwhile to get it back on, which is sometimes not a big deal.
John