As a curator of American history, the National Park Service can be the bearer of bad news. Sand Creek is not the only site that considers the dark side of our past.

Andersonville National Historic Site: During its peak, 45,000 Union soldiers were confined at the military prison maintained by the Confederacy at Andersonville in Georgia. Almost 13,000 died here. www.nps.gov/ande

Horseshoe Bend National Military Park: Horseshoe Bend, in eastern Alabama, commemorates an 1814 battle waged between 3,300 soldiers under Maj. Gen. Andrew Jackson and 1,000 Red Stick Creek warriors. More than 800 Red Sticks died that day, and the resulting treaty led to the cession of 23 million acres to the United States. www.nps.gov/hobe

Kalaupapa National Historic Park: Kalaupapa, on the Hawaiian island of Molokai, was the site of exile for Hawaiians who had contracted leprosy (Hansen's disease) in the aftermath of colonization. www.nps.gov/kala

Selma to Montgomery National Historic Trail: To protest the shooting of voting rights activists by an Alabama state trooper, thousands of demonstrators marched from Selma to Montgomery, Ala., on a route that crossed the Edmund Pettus Bridge. www.nps.gov/semo

Trail of Tears National Historic Trail: The Trail of Tears is a series of sites that commemorate the Cherokee who in 1838 were forcibly removed from their homelands in the southeastern United States and made to travel to Indian Territory, now Oklahoma. www.nps.gov/trte

Tule Lake Unit, Manzanar and Minidoka National Historic Sites: In 1942, 120,000 Japanese American citizens and resident Japanese aliens were incarcerated in 10 relocation camps throughout the western U.S. and Arkansas. The National Park Service has preserved three of these camps, Tule Lake Unit in Northern California; Manzanar, in Eastern California; and Minidoka in Idaho and Washington. NPS will open a fourth on Oahu. www.nps.gov/tule, www.nps.gov/manz, www.nps.gov/miin

Washita Battlefield National Historic Site: Lt. Col. George A. Custer led the 7th U.S. Cavalry in a surprise attack on Cheyenne camped along the Washita River in Oklahoma. Chief Black Kettle, a survivor of Sand Creek, was killed. www.nps.gov/waba