You will be given a definition of a task first, then some input of the task.
In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.

Captain George Vancouver ( 22 June 1757 – 10 May 1798 ) was a British officer of the Royal Navy , best known for his 1791 – 95 expedition which explored and mapped the northwest of North America , including the coasts of what are now Alaska , British Columbia , Washington , and Oregon .
Output:
Captain George Vancouver ( 22 June 1757 – 10 May 1798 ) was a British officer of the Royal Navy best known for his 1791 – 95 expedition , which explored and charted North America 's northwestern Pacific Coast regions , including the coasts of what are now the American states of Alaska , Washington , and Oregon , as well as the province of British Columbia in Canada .