Preservation of Lincoln's Two Drafts of the Gettysburg Address

In order to assure the long-term preservation of the two drafts of Lincoln's Gettysburg Address in the Library of Congress collections, the Preservation Directorate has commissioned the design and manufacture* of two state-of-the-art environmental containers, one for each document. In addition, the Library has constructed a low temperature vault where these containers and other Top Treasures of the Library will be permanently stored.
As can be seen in the one used [here] to display the Nicolay copy of the Gettysburg Address, the two containers are constructed of heavy-gauge stainless steel inner supports and two outer frames joined with neoprene gaskets and bolts, which allow access and viewing from both sides of the container. The containers are filled with low-moisture argon gas to purge the environment of oxygen, thereby virtually eliminating deterioration from oxidation, including photo-oxidation. The Mainz Bible case in which the sealed container is temporarily set, is conditioned to 49.5 degrees fahrenheit and 49% relative humidity. Even if the document were not sealed in argon, the constant low temperature of the case and the permanent storage area effectively quadruples its life expectancy.