1846: Architect and city planner Daniel Hudson Burnham was born in Henderson, New York. He moved with his family to Chicago nine years later. As a young man, Burnham worked in several Chicago architectural offices before joining fellow draftsman John Wellborn Root to establish a practice in 1873. The firm of Burnham and Root soon became central to the pioneering Chicago School of architecture, known for transforming the late-nineteenth-century urban landscape. With such structures as the Rookery Building (1886-88), Reliance Building, (1890-94) and Monadnock Block (1891), Burnham and Root helped to invent the modern skyscraper, changing forever our city skylines. (Source: Library of Congress)

1781: The City of Los Angeles, California, was founded.