Short answers, pulled from the story.
Chickamauga and Chattanooga National Military Park was officially dedicated in September 1895. Congress had authorized its establishment in 1890, making it the first of the four national military parks authorized during that decade.
The park owes its existence chiefly to Union Army of the Cumberland veterans General Henry V. Boynton and General Ferdinand Van Derveer. Ohio General Henry M. Cist also played a key early role, leading the Chickamauga Memorial Society in 1888.
The park covers 5,300 acres, making it the largest of the first four national military parks authorized by Congress in the 1890s. The others authorized during that decade were Shiloh, Gettysburg, and Vicksburg.
The park served as a major training and marshalling center during the Spanish-American War because of its proximity to the major rail hub at Chattanooga and its large tracts of open land. It was temporarily renamed Camp George H. Thomas during that period.
Moccasin Bend is an area directly across the Tennessee River from Lookout Mountain, significant for its archaeological record of American Indian settlement. It was added to the park as a new unit on the 20th of February 2003 under Public Law No. 108-7. It had previously been designated a National Historic Landmark on the 8th of September 1986.
The National Park Service assumed management of the park in 1933. Before that, the War Department oversaw the site, which was used for both military study and as a memorial during its early decades.