Louisa Catherine Johnson was born in London on February 12, 1775, the second daughter of Joshua Johnson, an American merchant from Maryland, and Catherine Nuth Johnson, an Englishwoman. Her father belonged to a politically connected Maryland family; his brother Thomas Johnson became the state’s first elected governor. Although born a British subject, she grew up in a household that identified strongly with the American cause and regularly received merchants, diplomats, and political visitors. The Revolutionary War repeatedly displaced the family. In 1778, Joshua Johnson’s support for independence helped prompt the Johnsons to leave England for Nantes, France. Louisa spent about five formative years there and attended a Catholic convent school. She excelled in languages, literature, and music, became fluent in French, and learned some Latin and Greek. Her immersion was so complete that she later recalled having to relearn English. The family lived elegantly in a large Nantes residence nicknamed the “Temple of Taste,” although Joshua’s finances were less secure than their style of life suggested. After the war, the Johnsons returned to London and settled near Tower Hill. Louisa entered an English boarding school, where classmates mocked her French accent and manners. The transition also created religious tension: Catholic practices learned in France conflicted with renewed Anglican instruction. She became self-conscious and withdrawn. The Reverend John Hewlett, an Anglican clergyman and family friend, subsequently supervised part of her education and encouraged her reading and intellectual interests. When the family’s finances worsened in 1788, she left school and continued studying with a governess. As a teenager and young woman, Louisa helped her family entertain the Americans who visited her father, appointed United States consul at London in 1790. She became an accomplished singer, harpist, and conversationalist.