The auxiliary steamship depict on this stamp of the USA in 2011 is designed after a contemporary lithograph of ships of the New York & Liverpool United States Mail Steamship Company (Collins Line.), New York.
Which ship is depict I could not find out, most probably designed after images of the ATLANTIC, PACIFIC, ARCTIC or BALTIC, the other vessels were two funnel ships.
One photo’s of this ships it looks that the paddlewheels are much more forwards as seen on the stamp, I can not find any of this ships under sail at a photo, most probably the designer of the stamp has taken some liberties for the design.
The company formed in 1847 had only 9 ships in the cross Atlantic trade during her existing, and they were not so lucky with her ships two were lost the ARCTIC and PACIFIC
The line could only achieved there contract speed at high cost and heavy wear and tear on the engines, and it became apparent that they were operating at a large loss.
When the two ships were lost soon after each other the company never recovered from the financial loss.
18 February 1858 the Collins Line suspended operations.
The ships were sold afterwards by the creditors.
USA 2011 sg?, scott?
More info on the company is given by Wikipedia http://en.wikipedia.org/wiki/Collins_Line