Humble stamp dealer Otto Becker has little to do with international politics, so when he receives a surprise visit from his estranged twin brother and Nazi spy, Baron Hugo von Detner, his world is thrown into turmoil. Threatening Becker with deportation, Hugo forces him to use his shop as a front for espionage.
Lem Schofield, a lawyer in a one-time small-town turned industrialized big city, runs his firm on examples set by Abraham Lincoln and is a friend to the poor. Clay Clinton, his late partner's son joins the firm but is anxious for fast success and considers Schofield's old-fashioned principles antiquated. Being in love with Schofield's daughter and impatient for success he moves to offices supplied by the city's most powerful industrialist, J.T. Tapley, who has plans to use Clay's good family lineage as a stepping stone to political power. The unscrupulous Tapley precipitates a strike in his factory mill which causes a rupture between the former partners. Schofield sets out to bring Tapley and his political henchmen to justice.
Fields plays "Larsen E. Whipsnade", the owner of a shady carnival that is constantly on the run from the law. Whipsnade is struggling to keep a step ahead of foreclosure, and clearly not paying his performers, including Bergen and McCarthy, who try to coax money out of him, or in McCarthy's case, steal some outright.
Alice, the only relatively normal member of the eccentric Sycamore family, falls in love with Tony Kirby, but his wealthy banker father and snobbish mother strongly disapprove of the match. When the Kirbys are invited to dinner to become better acquainted with their future in-laws, things don't turn out the way Alice had hoped.
In the 1840s, Ramsey MacKay, the driver for the struggling Wells Fargo mail and freight company, will secure an important contract if he delivers fresh oysters to Buffalo from New York City. When he rescues Justine Pryor and her mother, who are stranded in a broken wagon on his route, he doesn't let them slow him down and gives the ladies an exhilirating ride into Buffalo. He arrives in time to obtain the contract and is then sent by company president Henry Wells to St. Louis to establish a branch office.
In Vienna, a new jazz club featuring American trumpeter Buzzy Bellew threatens the existence of its neighbor, the Waltz Palace, run by Franz Strauss and featuring his granddaughter, singer Elsa. Smitten by Elsa, Buzzy hides his identity and association with the club -- whose owner intends to buy out the Palace property. When Elsa accidentally learns who Buzzy really is, it appears he may have to return to America alone.
Longfellow Deeds lives in a small town, leading a small town kind of life. When a relative dies and leaves Deeds a fortune, Longfellow moves to the big city where he becomes an instant target for everyone. Deeds outwits them all until Babe Bennett comes along. When small-town boy meets big-city girl anything can, and does, happen.