Fort Sumter today bears little resemblance to the imposing three-tiered brick fort of 1861 because more than 100 years of bombardment, reconstruction, and renovation reshaped it and extended its life. By the end of the Civil War in 1865, heavy shelling had reduced Fort Sumter to ruins. The fort was partially rebuilt in the 1870s, and many remnants of the original structure remain throughout the fort today. Battery Huger, the massive concrete structure in the center of the parade ground, was completed in 1899 in response to the Spanish-American War. Changes to Battery Huger kept pace with modern technology, and Fort Sumter continued as part of the U.S. coastal defense system until the close of World War II.