The assessment of the preservation of historic silks is discussed, using the First Ladies' gowns. At the Smithsonian's National Museum of American History, the state of preservation of each silk gown was examined, as well as the mechanisms involved in the degradation of silk. The formation of silk, from the Bombyx mori silkworm's cocoon and filament compositions are detailed. Exposure to light is the most detrimental to silk, causing physical and chemical damage. Some of the damage is outlined. Loss of fabric strength and color change are associated with oxidation and hydrolysis, chemical changes observed in protein degradation. Specific knowledge of the degradation mechanisms are unknown, so preventive care cannot always be done. Silk habutae was artificially aged and used as a test comparison with gown samples taken. A scanning electron microscope was used to test observed morphological alterations and surface characteristics. Color changes were assessed spectrophotometrically. Loss in breaking strength tests were not done, due to large sample sizes required. The advantages and disadvantages of the above tests are stated. Silk solubility and amino acid composition were better tests for determining the state of preservation than morphology or color determination. They also required small sample sizes. -- CAL