The United States developed and expanded rapidly in the first half of the nineteenth century. There were new inventions, new markets, new religions, and new social movements. But not everything was changing for the better: during this time, plantation slavery became ever more entrenched, and white settlers pushed American Indians ever farther west.

1932 CE, The Blue Wing Inn in Sonoma, California, was one of the first hotels built in the state north of San Francisco

1906 CE, From a main east-west trail, dating from antiquity, rises the great sandstone promontory of El Morro. Over the centuries, those who traveled this trail stopped to camp at the shaded oasis beneath these cliffs. They left the carved evidence of their passing - symbols, names, dates, and fragments of their stories that register the cultures and history intermingled on the rock. Explorers and travelers have known of the pool by the great rock for centuries. A valuable water source and resting place, many who passed by inscribed their names and messages in the rock next to petroglyphs left by ancient Puebloans. The ruins of a large pueblo located on top of El Morro were vacated by the time the Spaniards arrived in the late 1500s, and its inhabitants may have moved to the nearby pueblos in Zuni and Acoma. As the American West grew in population, El Morro became a break along the trail for those passing through and a destination for sightseers. As the popularity of the area increased, so did the tradition of carving inscriptions on the rock. To preserve the historical importance of the area and initiate preservation efforts on the old inscriptions, El Morro was established as a national monument by a presidential proclamation on December 8, 1906.

1876 CE - 1877 CE, In 1876, as the founders of Rapid City, South Dakota planned the layout of the city, Founders Rock attracted much attention for its prehistoric Native American rock art. The site of modern-day Founders Park, located along Rapid Creek, was previously utilized by the native Lakota and Cheyenne groups as a camp site to aid their movement through the Black Hills. The area later became home to various industries, including Rapid City's first electric power plant, a lumber mill, and a meat-processing facility. After a serious flood in 1972, the facilities shut down and the site became parkland. Today, Founders Park is a popular destination for hikers and rock climbers, and Founders Rock is particularly iconic for its unique inscriptions.

6000 BCE - 1880 CE, Rock Art of Colorado, The exquisite rock art at Gateway is hidden within the stunning landscape of sculptured rock that surrounds the western Colorado town. Two rock art sites at Gateway were selected for digital preservation, conducted between CyArk and local experts in 2014.

1942 CE - 1946 CE, Designated as a new unit of the National Park Service in February 2015 by Hawaiian-born President Barack Obama, the physical remains of the Honouliuli Internment Camp serve as a tangible reminder that during World War II, the U.S. government, under Executive Order 9066, forced over 120,000 people of Japanese heritage to leave their homes and businesses and live in confinement camps.

1200 CE - 1950 CE, Tutuveni and Dawa Park of the American Southwest

1849 CE - 1914 CE, John Muir worked, raised a family and wrote in his Martinez, California home.