USS Mount Vernon in 1919 (formerly Norddeutscher Lloyd "Kronprinzessin Cecilie" is seen in a large panoramic photo I recently purchased.  The photo is about four feet long, although it's only less than a foot tall.  It shows the ship returning to the US after a mission to bring troops back from Europe following World War I.
ABOVE, a detail view of the ship cropped to fit.  The KRONPRINZESSIN CECILIE was originally owned by the North German Lloyd Line (Norddeutscher Lloyd in German) and was the fourth and last four-stacker of that line.  (This company's major competitor in Germany was Hamburg-America which built only one four-stacker with which to compete.)  These large and expensive ships were really intended to gain notoriety for the largest German shipping lines, and shipbuilding, over the British and to get the Blue Riband for transatlantic speed away from the British.  This they did (although the British got it back later) but what they really did was launch the era of the "Super-Liner" and of course being the first four-stack ocean liners ever built they also started the notion that four stack ships were the biggest, best and safest group (which of course has nothing to do with the number of stacks, per se.)

The Kronprinzessin Cecilie itself (built 1906-1907, first sailing August 1907) had a notable career before it became the USS Mount Vernon.  Although it was completed about the time of the legendary turbine-powered, record-breaking British Lusitania and Mauretania, the Kronprinzessin Cecilie represented (according to Denis Griffiths in his book "Steam at Sea") the ultimate development of reciprocating (piston-type) steam engines in ships.  This ship was credited with over 45,000 IHP on two shafts; this was developed by four three-crank four-cylinder quadruple-expansion engines mounted two on each propeller shaft (two shafts.)  Earlier German ships in the four-stack class used two very large engines, with less total power but in order to take the step to this level of power four engines were used.  The ship had twelve double-ended boilers in four spaces - hence the four stacks.  This ship was very likely the most powerful reciprocating steam-engined ship ever built.

The ship was further noted for its famous ruse on the outbreak of war.  According to William J. Miller Jr. in the book "The First Great Ocean Liners in Photogra?phs" the ship was on its way to Germany in late July 1914 but was still near the US coastline when word of imminent hostility in Europe was received by wireless.  The ship had many millions of dollars worth of gold bullion and silver bars on board, headed to Germany and the crew knew it; they also knew that capture (or worse) by the British would be likely.  They decided to stop communications, darkened the ship and essentially hid the ship in motion.  According to many sources, and Miller as well, some of the passengers were delighted with the intrigue while others panicked; still others tried to purchase the ship so that it could be considered as being US-registered.  (Obviously, secrets don't keep well on even large ships.)  This last plan would never have worked since the crew didn't have the right to sell the ship - but it would have been a massive bribe anyway.  The captain decided to repaint the funnels into the colors of the British-owned White Star Lines, and anchored the ship near Bar Harbor, Maine.  No one was fooled for long, and the ship, which was essentially helpless and full of now-not-too-happy passengers, was given to the United States by the crew.

Several other German ships (some newer and larger) were in US hands as well, and when the US entered the conflict the value of these ships was seen and they were all converted into troop transports.  Kronprinzessin Cecilie became the USS Mount Vernon, and the US Navy operated the ship through the rest of the conflict and after, ferrying troops to and from Europe and other parts of the world. 
Here we see part of the photo, with the inscription:  "Mt. Vernon Arrived April 4th, 1919, 26th Yankee Division.  Formerly German Liner, "Die Kronprinzessin Cecilie."  Home at Last."  The ship is being pushed to the dock by the harbor tugs, and servicemen are visible all over the ship.

The US Navy had no further use for the ship but apparently the US Army did, so that unusually the ship was transferred to the Army and still carrying the name Mount Vernon was operated by that service beginning in 1920, but only for a year or two (this data is difficult to verify.)  In a short time the ship was out of service, and was turned over to the Maritime Administration which stored it.  The ship lay (with other ex-German liners) unused until war again broke out; she was offered to the British but the offer was declined, so that the ship was scrapped in 1940.
Click here to see a BIG version of almost the whole photograph.