New Orleans's Garden District and "Uptown" neighborhoods were settled in the 1840's by successful entrepreneurs and well-to-do merchants and bankers. They built large, elegant mansions exemplifying many architectural styles, including Greek Revival, Italianate and Queen Anne Victorians. Numerous cash crops such as cotton, sugar, coffee and national banks all fueled the local economy. Following the Louisiana Purchase in 1803, Americans had swarmed into New Orleans to take advantage of the boom in Mississippi River commerce. By the 1830's, New Orleans was "flush." Friction between the arriving Americans and the mostly Creole residents of the already crowded French Quarter resulted in the prosperous Americans moving upriver to create their own residential districts of opulent mansions in the city of Lafayette, which was annexed to the city of New Orleans in 1852, and further upriver. Mark Twain, frequent guest at the Garden District home of his friend and lecture circuit partner George Washington Cable, wrote, "the mansions stand in the center of large grounds and rise, garlanded with roses, out of the midst of swelling masses of shining green foliage and many-colored blossoms. No houses could be in better harmony with their surroundings, or more pleasing to the eye, or more homelike and comfortable looking.".