William McCully and Company Glassworks in Pittsburgh, Pennsylvania manufactured bottles in the mid 19th century. Bottles found with the embossing “McC & C” or “Wm. McC & CO” can be attributed to them.
Here is an envelope from the business which has a really fine engraving of the company office as well as the manufacturing buildings. Click to enlarge.
This envelope with its “cameo” illustration is earlier: