ALERT: Dome Restoration Project Necessitates Rotunda Closure April 12 through April 28.
Click here for more information.

History of Congress and the Capitol

This is the story of one of the world's great experiments in government by the people.

For more than two centuries, a new Congress has convened every two years following elections that determine all the seats in the House and one-third of those in the Senate. While the individuals change, the institution has endured-through civil and world wars, waves of immigration and great migrations, and continuous social and technological change.

See More

Filter by Year:

Unprecedented growth in the 1850s strained the fragile agreements that had kept the nation united, but had also kept it part slave, part free. The addition of each new state to the Union rattled the delicate political balance carved out by compromises in Congress. In 1854, the Kansas-Nebraska Act allowed residents of each of these new territories, rather than Congress, to decide whether to permit slavery. While intending to keep the nation together, this act inflamed sectional tensions, producing open warfare between pro- and antislavery forces in Kansas, and led directly to the Civil War.

See More

The House of Representatives 1851-1877

Defending the Union

Sectional divisions blocked House business before the Civil War. When war came, the House concentrated on winning.

With peace, the House turned to issues of recovery. The House remained deadlocked even as conflict loomed. But Southern congressmen soon defected to the Confederacy, freeing Republican representatives to act. They abolished slavery in territory held by Union troops and passed long-stalled bills to build railroads and open land to homesteaders. After the war, Republicans demanded that the House punish rebels more harshly than Presidents Abraham Lincoln and Andrew Johnson recommended. Ultimately, their agenda faltered under its own weight. Republicans failed to remove President Johnson through impeachment. Moreover, the effective resistance of former Confederates frustrated their vision of reshaping the South, socially and economically.

Partisan Politics and the Radical Republicans

In the deeply divided house, balances between parties and regions proved critical. No one bloc dominated, but antislavery Republicans were gaining support. The House remained deadlocked. When the South seceded, however, the logjam broke and Republicans like Thaddeus Stevens assumed unchecked power. After the ambitious postwar Reconstruction failed, a new political era arose in which fresh debates about national economic development replaced old battles about sectionalism and slavery.

View All Photos from The House | Back to Top
The Senate 1851-1877

All Compromise Fails

Secession of Southern states and the outbreak of war fostered unity among those who remained in Congress. Senators passed bills to meet wartime emergencies and spur economic development.

After the Civil War, the Senate’s large Republican majority aimed to set policies for reconstructing the South and protecting freed slaves, and members hotly disputed President Andrew Johnson’s more lenient policies toward the former rebels. This power struggle led the House to impeach Johnson. He was acquitted at his Senate trial by one vote.

Conflicting Loyalties

War brought rapid change to Congress. By 1862, the Senate had expelled 14 members for disloyalty to the Union. It also created a loyalty oath to ensure that former Confederates could not simply return to national office. During postwar Reconstruction, when newly readmitted Southern states again elected senators, Mississippi elected the Senate’s first two African-American members.

View All Photos from The Senate | Back to Top
The Capitol 1851-1877

A Symbol for the Nation

A dramatic transformation reshaped the Capitol in the middle of the 19th century as expansion and additions created the structure familiar to us today. New wings flanking the earlier structure tripled the size of the Capitol.

A taller and highly decorated iron dome replaced the plain wooden structure that had previously topped the building.

During the Civil War, the Capitol emerged as a powerful symbol of national unity. It served as a stirring landmark for countless soldiers who marched through Washington determined to see the Union restored and to see the Capitol—particularly its grand new dome—completed.

View All Photos from The Capitol | Back to Top

Images of the Era - 1851-1877

  • While the Civil War raged, a great cast-iron dome was added to the Capitol, symbol of an enduring nation.

    While the Civil War raged, a great cast-iron dome was added to the Capitol, symbol of an enduring nation.

    Architect of the Capitol

  • South Carolina seceded from the Union in December 1860, followed by 10 other Southern states.

    South Carolina seceded from the Union in December 1860, followed by 10 other Southern states.

    Prints and Photographs Division, Library of Congress

  • Confederates burned Richmond, Virginia, their capital, before it fell to Union forces in April 1865.

    Confederates burned Richmond, Virginia, their capital, before it fell to Union forces in April 1865.

    Prints and Photographs Division, Library of Congress

  • President Lincoln’s Emancipation Proclamation of January 1, 1863, freed all slaves in Confederate-controlled territory.

    President Lincoln’s Emancipation Proclamation of January 1, 1863, freed all slaves in Confederate-controlled territory.

    Prints and Photographs Division, Library of Congress

  • At Gettysburg, in 1863, the bloodiest battle of the Civil War ended the Confederate army’s northward advance.

    At Gettysburg, in 1863, the bloodiest battle of the Civil War ended the Confederate army’s northward advance.

    Prints and Photographs Division, Library of Congress

  • John Wilkes Booth, a Confederate sympathizer, assassinated President Lincoln at Ford’s Theater, April 14, 1865.

    John Wilkes Booth, a Confederate sympathizer, assassinated President Lincoln at Ford’s Theater, April 14, 1865.

    Prints and Photographs Division, Library of Congress

  • The nation celebrated its 100th anniversary with a grand exhibition in Philadelphia, 1876.

    The nation celebrated its 100th anniversary with a grand exhibition in Philadelphia, 1876.

    Prints and Photographs Division, Library of Congress

  • Japan’s first emissaries to the United States exchanged treaty ratification papers and visited Congress in 1860.

    Japan’s first emissaries to the United States exchanged treaty ratification papers and visited Congress in 1860.

    Alexander Gardner and Mathew B. Brady, The Japanese Ambassadors, First Japanese Mission to the United States, ca. 1860, salt print, 15 x 16 3/16 in., The J. Paul Getty Museum, Los Angeles

  • Soldiers of the 4th U.S. Colored Infantry defended Washington, D.C. After January 1863, African-American soldiers made up almost ten percent of the Union Army.

    Soldiers of the 4th U.S. Colored Infantry defended Washington, D.C. After January 1863, African-American soldiers made up almost ten percent of the Union Army.

    Prints and Photographs Division, Library of Congress

  • After the Civil War, African-American men gained political influence when the Fifteenth Amendment ensured their voting rights.

    Prints and Photographs Division, Library of Congress

  • The Freedmen’s Bureau, established in 1865, provided assistance and education to former slaves.

    The Freedmen’s Bureau, established in 1865, provided assistance and education to former slaves.

    William Gladstone Collection

  • Congress founded Howard University, one of several new colleges for African-Americans, in 1867.

    Congress founded Howard University, one of several new colleges for African-Americans, in 1867.

    Moorland-Spingarn Research Center, Howard University

  • The 1862 Pacific Railroad Act spurred the Union Pacific to complete a transcontinental rail link.

    The 1862 Pacific Railroad Act spurred the Union Pacific to complete a transcontinental rail link.

    The Andrew J. Russell Collection, the Oakland Museum of California

  • Chinese immigrants provided much of the labor for construction of the transcontinental railroad.

    Chinese immigrants provided much of the labor for construction of the transcontinental railroad.

    Prints and Photographs Division, Library of Congress

  • On the tree-sparse grasslands of the Great Plains, many homesteaders built houses of sod.

    On the tree-sparse grasslands of the Great Plains, many homesteaders built houses of sod.

    Nebraska State Historical Society, RG2608 PH 0 1249, copy and reuse restrictions apply

  • Sitting Bull’s Sioux and Cheyenne warriors won a battle against the U.S. Army at Rosebud River, Montana, 1876.

    Sitting Bull’s Sioux and Cheyenne warriors won a battle against the U.S. Army at Rosebud River, Montana, 1876.

    Prints and Photographs Division, Library of Congress

  • Government schools in the late 1800s aimed to integrate Native Americans by forcing them to adopt European dress and speak English.

    Government schools in the late 1800s aimed to integrate Native Americans by forcing them to adopt European dress and speak English.

    Cumberland County Historical Society, Carlisle, PA

  • Designing a New Dome

    The Capitol developed into its current majestic form through enlargements and a new dome that were designed by Thomas U. Walter of Philadelphia. When he came to Washington in 1851, Walter was already one of the nation’s leading architects. He had designed Girard College in Philadelphia, private mansions and villas, churches, commercial buildings, and engineering projects located up and down the east coast and as far away as Venezuela. It was, however, his work for the federal government—especially the Capitol’s great iron dome—that placed him at the pinnacle of the architectural profession and secured his enduring place in American history.