Adams, Gabriel, Mayor, [51]
Alexander, John W., [91], [106]
Allegheny, made county-seat, [40];
county-seat changed to Pittsburgh, [40];
annexed to Pittsburgh, [52]
Allegheny Cemetery, [90]
Allegheny County, erection of, [40];
iron and steel products of, [84]
Allegheny Observatory, [84], [99]
Allegheny River improved, [82]
Allegheny Theological Seminary, [102]
Amalgamated Association of Iron and Steel Workers, [71], [78]
Amherst, General, captures Fort Frontenac, [29]