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Before mechanical refrigeration, ice was used to preserve perishable food. In winter, slaves cut pieces of ice from the frozen Potomac river. They tossed the ice into a brick pit lined with wood. The "house" was merely a cover for the pit. The ice was periodically pounded into one solid mass and packed in straw to slow the melting process. When ice was needed, it was hacked off with an axe. Although this particular structure was built after George Washington's death, his original icehouse, located less than 100 yards from the river, was used in the same fashion.
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