Canning technology had just begun to be developed, and it gained in popularity through the period of westward expansion. Initially, only upper-class migrants typically used canned goods. There are references in sources to canned cheese, fruit, meat, oysters, and sardines. By the time Marcy wrote his 1859 guide, canned foods were increasingly available but remained expensive. Canning also added weight to a wagon. Rather than canned vegetables, Marcy suggested that travelers take dried vegetables, which had been used in the Crimean War and by the U.S. Army.