I found another resource for gathering information on soldiers yesterday. It’s been around a while, but it’s new to me.
Allegheny County, Pennsylvania, in the War for the Suppression of the Rebellion, 1861-1865, by Samuel M. Evans, lists all of the army and navy volunteers from Allegheny County who fought in the Civil War. Entries include name, rank, company, regiment, type of service, and which tablet number the individual is listed on in Soldiers and Sailors Memorial Hall in Pittsburgh.
It is available here through the University of Pittsburgh Digital Research Library. It is based on a printed work of the same title published in Pittsburgh in 1924.
There’s some great information here. Much to my delight, I’ve found lists of three companies from the 6th US Cavalry, as well as discovering that scores of the members of the 1st MD Cav, 1st and 5th WV Cav, and 70th NY Inf were in fact Pennsylvanians.
Regular Cavalry in the Civil War 
While not Calvary, you might fond this on the 3rd NC Mounted Rifles (USA) interesting. I will be back.Rexx http://blog.360.yahoo.com/blog-PVuDo04lc6O14vQA7MZwc06iUGDpBFEDCg–?cq=1&p=434#comments
Interesting, Rex, I’d never heard of that unit before.
Don,Could you contact me on private email? I lost your addy – hopefully you still have mine.Harry Smeltzer
Samuel P. Bates, History of Pennsylvania Volunteers, 1861-5 is a detailed history of the various regimental units from Pennsylvania that participated in the Civil War. The Pennsylvania state legislature directed that such a history be written and paid for it. Each state was required to prepare such a history. Pennsylvania did a magnificent job. I found a copy of the two volume set at Stanford University’s Green library.
Other web sites of note:wvcivilwar.com West Virginia in the Civil Warlindapages.com/wvcw/1wvc/1wvc.htm First West Virginia Cavalry. Project of Linda Cunningham Fluharty. She also has contributed much to wvcivilwar.com
… many West Virginia Civil War soldiers mustered in at Wheeling, Virginia came from the Wheeling valley in Pennsylvania–the territory southwest of Pittsburgh.
Tom,Thanks for the tips. The Bates history is also available online through the paroots site. If it was in Stanford’s library it may be available for free download now also. I wish some other states (NY, for example) had been as diligent.I guess the Wheeling valley is in or very near to Allegheny County, given how many memebers came from there.