Theodore Vail was presented with a certificate in honor of the achievements of his company. In elegant calligraphy, the certificate describes AT&T's contribution to "the art of telephony." You can view this certificate and a plain text version of the copy scrawled across it by clicking on the thumbnails on this page.
The certificate reads:
"in recognition of its constructive and far-seeing policy in the development of the art of telephony; in the promotion of telephone engineering; in the establishment of its telephone system in every part of the United States, and for placing all of the States of the Union in speaking communication."