Map of the Exhibition complex —
Photo Credit: By Boston Public Library - Public Domain, https://commons.wikimedia.org/w/index.php?curid=26553064

Opening day ceremonies at the Centennial Exhibition — Philadelphia, PA May 10, 1876
Photo Credit: By James D. McCabe - Public Domain, https://commons.wikimedia.org/w/index.php?curid=20251367

Centennial International Exhibition 1876 — Share of the Centennial Board of Finance from the 18. August 1875 for the Centennial International Exhibition 1876
Photo Credit: By Unbekannte Autoren und Grafiker - Public Domain, https://commons.wikimedia.org/w/index.php?curid=71156277

A Bell System logo — A Bell System logo (called the Blue Bell), used from 1889 to 1900. The Bell Telephone Company and its successors created the Bell System and drove its expansion.
Photo Credit: By AT&T - http://www.porticus.org/Transferred from en.wikipedia by SreeBot, Public Domain, https://commons.wikimedia.org/w/index.php?curid=17836546

Alexander Graham Bell Family 1885 — Mabel Gardiner Hubbard with her husband Alexander Graham Bell and their daughters Elsie (left) and Marian (1885).
Photo Credit: Public Domain, https://commons.wikimedia.org/w/index.php?curid=5341873

Mabel Hubbard Gardiner Bell as a girl, ca. 1860 —
Photo Credit: By Unknown -Public Domain, https://commons.wikimedia.org/w/index.php?curid=77358492

Mabel Gardiner Hubbard Bell (c. 1917) — wife of Alexander Graham Bell
Photo Credit: By Harris & Ewing - Public Domain, https://commons.wikimedia.org/w/index.php?curid=10906134

Gardiner Green Hubbard —
Photo Credit: By Otto Renard - Library of CongressCatalog: Public Domain, https://commons.wikimedia.org/w/index.php?curid=79883978

Bell's Master Telephone Patent — US Patent #174465, March 7, 1876
Photo Credit: By U.S.P.T.O. - Public Domain, https://commons.wikimedia.org/w/index.php?curid=12202170

Alexander Graham Bell —
Photo Credit: By Moffett Studio - Library and Archives Canada / C-017335, Public Domain, https://commons.wikimedia.org/w/index.php?curid=1559

Tivadar Puskás —
Photo Credit: By Unknown - vmek.oszk.hu, Public Domain, https://commons.wikimedia.org/w/index.php?curid=14241811