Her economic problems lay primarily in high labor costs and fuel costs which were compounded by Prohibition. From 1920 all US registered ships counted as an extension of US territory, making them "dry ships" according to the National Prohibition Act. With the Atlantic shipping capacity oversaturated, especially after the Immigration Act of 1924, alcohol-seeking passengers readily chose other liners. But "Leviathan" was an American symbol of power and prestige, which despite her economic failings, made her a popular ship with loyal travelers. She attracted attention as the largest and fastest ship in the American merchant marine and featured in countless advertisements. The only serious incident occurred one day out of Cherbourg on a winter crossing in 1924 where she met a fierce storm with 90 ft waves and winds up to 100 mph, at times forcing her into 20 degree rolls. Eleven portholes were smashed and 32 passengers injured by the time the storm abated.