Short answer is no. As per immigration stats to the US from the years 1912, 1913, 1914 show, Titanic's sinking in 1912 did not dent the rising trend of new immigrants migrating to United States.

Since Britannic never formally became an ocean liner (she became a hospital ship and then sunk in WWI), there isn't really a before/after figure to compare to.

• 1912: 838, 172

• 1913: 1,197,892

• 1914: 1,218,480

Data is pulled from the Migration Policy Institute's statistics on Annual Legal Immigration to the US (1820-2013)

http://www.migrationpolicy.org/programs/data-hub/us-immigration-trends

The Titanic sunk on her maiden voyage, and the Britannic was only ever a hospital ship, so, in terms of immigration, it's like they didn't exist at all.

I mean, it's not as though there were a fixed number of ships or anything -- the White Star Line (like many shipping lines) had ships requisitioned by the Admiralty for use in WWI, but received German ships seized as reparations after the war (in the early 1920s or so, iirc). The loss of carrying volume represented by the sinking of the Titanic and Britannic was taken up by other ships, and the fiscal loss was covered with insurance.

No, but that was largely to do with the Immigration Act of 1924, which I don't know too much about so maybe an American historian can elaborate on that.

And like others have said, shipping lines had other ships. The Titanic and Britannic were just two ships (albeit large for the time) in one ocean line company in one country. The Britannic (and Cunard's smaller Lusitania) were replaced by two even larger German superliners (The Bismarck/Majestic for White Star, the Imperator/Berengaria for Cunard) after the war. They were also the express luxury liners for the important New York route where steerage passengers were a secondary consideration. In those days, cruising as we know it was in its bare infancy so it wouldn't make sense to dedicate an entire ship to first class accommodations. Shipping lines also had older, smaller, slower ships that went to secondary ports like Boston or to Canada and were mostly third class.