What percentage of americans can trace at least one ancestor to ellis island?

40%

Explanation:

It estimated that around 40% of the Americans trace their at least one ancestor to Ellis Island.  Ellis Island became to be known as the gateway to America for the immigrants who came in the late 1800s. The island facility processed more than 12 million immigrants until November 1954, when the immigration stopped by the Government by closing Ellis Island.

the alfred thayer mahan award for literary achievement is awarded each year by the navy league of the united states. the award is named for an american naval historian and theorist, rear admiral alfred thayer mahan, united states navy who, through his writing, provided stimulus and guidance to those who share in the defense of the nation. presented since 1957, "this award for literary achievement is awarded to a u.s. navy officer, u.s. marine corps officer, enlisted service member, or civilian who has made a notable literary contribution that has advanced the knowledge of the importance of sea power in the united states."[1]