Passenger No. 42 on the S.S. Marsala from Hamburg, arriving August 26, 1893, was one Willy Brandt, age 15. Calling or occupation, none. Native country, Prussia. Last residence, Gottingen. Destination, New York.

In "Germans to America," a photo exhibit at the Smithsonian Castle, a passenger list tells tales of real people: Brandt's fellow travelers encompassed the trades of the day -- farmer, laborer, locksmith, clark; seaman, glovesmaker, tin man, smith. Some brought wives. Coming from Bavaria, Hamburg and Bohemia, they were heading for New York, Illinois, Missouri, Iowa and California.

But young Brandt and the others on the ship were less than a ripple in the flood of immigrants that followed the first German- Americans -- who, lured by William Penn, had arrived on the Concord in 1683 to give birth to Germantown, Pennsylvania.

And this is the reason for the exhibit, President Reagan having proclaimed 1983 the Tricentennial Year of German Settlement in America.

It's a modest show of 50 panels, little more than a stopping place in the Associates Lounge on the way to a dining room, but it may give pause to at least 28 percent of the people who walk past. That, according to 1980 census figures, is the percentage of Americans who can claim German ancestry.

It will also interest anyone wearing jeans: The exhibit notes that Levi Strauss arrived in 1845 to join the California Gold Rush, bringing with him from Bavaria a bolt of sailcloth which he used to make practical clothing for the miners. GERMANS TO AMERICA, 300 YEARS OF GERMAN IMMIGRATION -- In the Lounge of the Smithsonian Castle through April 7.