Bill wants to join the Army, but he's 4F so he asks a wizard to help him, but the wizard has slight problems with his history knowlege, so he sends Bill everywhere in history, but not to WWII.

Bill Morgan despairs when he tries to enlist in the Navy and is rejected as a 4-F, as he was by the Army. He goes to the New York U.S.O. canteen where Lucilla Powell, with whom he is in love, works, but Lucilla only has eyes for men in uniform. Lucilla tricks Bill into washing dishes, and he is aided by Sally, a sensible young woman who cannot compete with Lucilla's glamour. Bill is unaware of Sally's feelings for him, just as he is unaware of Lucilla's true, shallow nature. After finishing the dishes, Bill tries to talk Lucilla into a date, but she snubs him for a serviceman. Dejected, Bill returns to his scrap metal yard, which he sees as his only way to contribute to the war effort. There, an elderly woman brings in a load of junk, including an antique lamp. After the woman leaves, Bill is astonished to hear a man's voice begging to be released from the lamp. When Bill drops the lamp, a genie named Ali materializes from its remains and thanks Bill for freeing him. Bill is stunned but quickly recovers when Ali promises him some wishes for his good deed. Bill states that all he wants is to be in the Army, but when he emerges from Ali's magic cloud of smoke, he finds himself at Valley Forge in 1776. The troops with which Bill marches stop at a U.S.O. canteen for coffee, doughnuts and dancing, and Bill is entranced by a hostess named Prudence Smith, who bears an uncanny resemblance to Sally. Bill is distracted from Prudence, however, by the appearance of General George Washington and Benedict Arnold. When he finally speaks to Washington alone, Bill recalls his history lessons from Miss Hockheimer of Bronx High School and assures the general that Arnold is a traitor. Bill also volunteers to spy among the Hessian troops and goes to a tavern, where he meets a flirtatious waitress named Gretchen, who reminds him of Lucilla. Bill almost gets away with his spying mission, but is caught by General Rahl, who sentences him to be shot. Just as he is about to be killed, Bill is whisked away by Ali, whose good intentions continue to be thwarted by his magic timepiece, which is still broken. Although Ali succeeds in getting Bill into the Navy, he winds up on the Santa Maria with Christopher Columbus in 1492. Bill arrives just as disgruntled sailor Benito leads his fellow seaman in a mutiny against Columbus, but Bill is able to persuade them to stop. They soon discover land and Bill sets off in a sailboat for New York. He lands at Manhattan Island, where he is entranced by the sight of a curvaceous Indian woman undressing inside her tepee. Bill's happy exclamation at her show causes the woman to faint, and when Bill checks on her, he is forced to shoo away an encroaching bear. Bill is next terrified by the appearance of the woman's husband, Chief Badger, who threatens to scalp him. Bill talks the chief into selling him Manhattan for twenty-four dollars, but at the conclusion of their deal, finds that he has been swindled by the chief, his wife and their pet bear, who have perpetuated "the old badger game" on him. Bill finally realizes that the "Lucilla type" is not for him, and wishes that he could see the faces of the old Dutchmen when they discover that he owns Manhattan. Ali then transports him to Nieuw Amsterdam of the early 1600s. A respected blacksmith, Bill is enjoying the time period when he is confronted by obnoxious businessman Kreiger, who asserts that he is marrying the girl Bill loves. The woman turns out to be another Sally double named Katrina, and Bill realizes that she is indeed the woman for him. She is being forced to marry Kreiger, however, because he holds the deed to her father's farm. Determined to save Katrina, Bill approaches the city council and proves that he owns Manhattan with the deed signed by Chief Badger. He sells the island to them, but after they levy a series of taxes on him, Bill ends up owing them money and is thrown in jail. He is joined by the inebriated Ali, who helps him rescue Katrina from her wedding to Kreiger, then takes them on a ride through the centuries. When they arrive in the twentieth century, Ali kicks Bill out of the car into a recruiting station, and Katrina becomes Sally. Bill is accepted into the Marines and marches with them in a parade, although Ali at first has him marching with the Women's Marine Reserves. Safely installed among the men, Bill assures Sally of his love, while Ali is accosted by two policemen, who are suspicious of the 854 B.C. birthdate on his draft card. Ali wishes himself into the Marines, and is joined by Lucilla as he marches alongside Bill, who is accompanied by Sally.