From: http://www.myinsulators.com/glass-factories/bottlemarks.html
C C & Co (monogram)..........Carl Conrad & Company, St. Louis, MO. Carl Conrad was a distributor of bottles made for Anheuser-Busch Brewing Company. Conrad was not an actual glass company. Best guess for the time period during which bottles were made with this base marking would be from about 1876 to 1885. Most were made in a distinctive pale blue-aqua glass. Some of these bottles also carry side embossing including the brand name "Budweiser", although many are unembossed except for the CC&Co basemark. Some specimens carry a glassmaker mark as well (such as D.O.C.--- D. O. Cunningham Glass Co., Pittsburgh) but many of these bottles without a glassmaker ID were probably made by one of several local St. Louis-area glass factories, such as Lindell Glass Company, Mississippi Glass Company, Belleville Glass Company, or Illinois Glass Company. (Adolphus Busch Glass Manufacturing Company did not come into existence until 1886, at which time the Belleville Glass Company was purchased by Adolphus Busch).