The U.S. Army Corps of Engineers, charged with maintenance and public building in the District of Columbia, took a great interest in public improvements after the Civil War. Various officers traveled to Europe and studied public works; a nationalistic industrial age was flourishing, notably in France and Germany. Among the many projects of the Corps of Engineers that never got far from the drawing table was a new White House. Plans had been drawn up for a "suburban palace" located in the picturesque area now known as Rock Creek Park. President Andrew Johnson approved the idea in 1867. But when President Ulysses S. Grant came to office in 1869 as the peacemaker, he recognized the symbolic power of the White House and would entertain no notions of a new one.
The existing White House instead became the focus of improvements. The aftermath of the Lincoln assassination had left the house (which had been overused during the war) fairly well torn up, with the public moving idly in and out while Mrs. Lincoln lay upstairs consumed by grief. President Johnson, knowing he would never live in a new mansion if one was begun, accomplished a complete refurbishing of the interior. The office was refurnished except for Andrew Jackson's portrait and desk, and a telegraph was installed in the southeast corner room of the office suite. A greenhouse built on the roof of the west terrace in 1857 to house plants from the former orangery caught fire in 1867 and was replaced with a greenhouse of iron, opening directly into the house. This was enlarged by Grant, who had a billiard room constructed between the house and the greenhouse; other glass extensions rambled over the west wing. Subsequent presidents had additional greenhouses built. Palms, cactus, orchids, camellias, spring bulbs, water plants, all flourished under the care of expert gardeners. A rose house stood on the site of today's open-air Rose Garden.
The presidents welcomed the privacy that the greenhouses afforded. For some they were a promenade and for others a place for rest beneath the glass ceilings. First Ladies liked their floral bounty. Bouquet makers were employed making gift bouquets to send by coachman to hotels and boarding houses, substituting for the personal calls First Ladies traditionally made to congressmen and senators' wives and important women visiting town. If any one feature characterized the Victorian White House it was the "glass houses" or "conservatories" that stood as large and exotic companions to the historic building.
Efforts by President Chester A. Arthur in 1881 to demolish and replace the White House came to nothing and even raised some hackles. He proposed a modern wing, with a "bridge of sighs" connecting it to the original structure, and various plans survive. The Corps of Engineers continued to await its moment to improve the presidential complex; if one thing had been learned, it was that the old White House would remain. With this in mind, the Corps began preparing plans for adding to the house in the architectural manner established by the original building. When her husband, Benjamin Harrison, came to office in 1889, First Lady Caroline Harrison oversaw various improvements to the White House, including the installation of electricity in 1891. She met with the engineers to discuss a major expansion of the house, to mark the one hundredth anniversary of George Washington's inauguration as president. With her participation, the Corps produced detailed plans for such an expansion.
The idea was to create a quadrangle to the south, faced on one side by the south façade of the White House and on the east and west, with new space for art galleries, presidential offices, and guest rooms, and at the far south end with new greenhouses, which, because the grade slopes downward, would not obstruct the historic view of the river. Congress was not entirely opposed and a bill was born. However, Harrison appointed a certain postal official in Maine without consulting Speaker Thomas Brackett Reed from Maine (known in his day as "Czar Reed"), and Reed retaliated for what he considered a slight by obstructing passage of the bill. The celebration of Washington's inauguration went on with considerable glitter but without a new White House.
Encouraged by construction of the massive Jefferson Building of the Library of Congress in the 1890s and the building projects of the 1893 World's Columbian Exposition in Chicago, the Corps of Engineers in collaboration with the architectural designer Frederick Owen, continued to refine their plans for an enlarged White House. Grover and Frances Cleveland gave an idle nod to the idea. Cleveland's successor William McKinley, president from 1897 to 1901, was generally agreeable, and the Corps, under the public buildings commissioner Colonel Theodore Bingham, planned to present its new project as part of the one hundredth anniversary of the first occupation of the White House by John Adams. In 1900 the Corps unveiled an elaborate model, tailored to please McKinley with its inclusion of a press wing. Mrs. McKinley's remark, "There won't be any hammering while I live here," was hardly heard amid the enthusiasm of Bingham and his supporters.
Objections were soon voiced by various political figures, not the least of whom was Senator James McMillan of Michigan, chairman of the District Committee and Centennial Committee of Washington City. Urged on by the American Institute of Architects and his aide Charles Moore, McMillan rallied support for a comprehensive parks system for Washington, which took the form of an Act of Congress on 8 March 1901. The issue of White House expansion, although pushed by the Corps, receded, and McKinley's assassination in September put the plan in limbo.