My pick of technology-related headlines from The New York Times Page One 1851-2002:
[10/18/1907] Signalizing the opening of the Marconi Service to the public, and conveying a message of congratulation from Privy Councillor Baron Avebury, formerly Sir John Lubbock
[01/08/1927] Opening new radiophone service; First private call to The New York Times
[10/05/1957] The Naval Research Laboratory announced early today that it had recorded four crossings of the Soviet earth satellite over the United States
[07/21/1969] Astronauts land on plain; Collect rocks; Plant flag
Since the most important technological developments in the time period covered occured in the western world, and since The New York Times can safely be assumed to best mirror these developments, notwithstanding the selective sample included in Page One, I consider these to be our most important technology-related headlines from 1851 to 2002. Although, sometimes technological change can seep in without so much as a loud knock or one bold headline [think Internet].
For those wondering about a headline that may seem conspicuous by its absence, say one that heralds the omnipresent automobile, keep in mind the time period covered. It is widely accepted that the automobile, for example, was invented by France’s Nicolas Cugnot between 1725-1804.
From the same source, my pick of highly arguable socio-political turning points important to a broad American psyche:
[12/08/1941] Japan wars on US and Britain
[08/07/1945] First atomic bomb dropped on Japan
[05/18/1954] High Court bans school segregation
[04/30/1975] Minh surrenders, Vietcong in Saigon
[09/12/2001] US attacked