Jonathan and Juliet Lemmon (defendants) owned slaves. The Lemmons were residents of Virginia, where slavery was legal. The Lemmons began traveling with eight slaves to Texas, another slave state, by way of New York, as this was the easiest route. New York was not a slave state and had a law stating that any slave brought into the state for any purpose would be freed automatically. The Lemmons had no intent to sell the slaves while on their trip. While their ship was docked in New York Harbor overnight, the Lemmons kept the slaves on land in New York. A citizen of New York, Louis Napoleon (plaintiff), petitioned for a writ of habeas corpus, arguing that the slaves, on land in New York, were free. The Lemmons argued that their only purpose of temporarily being in New York was mere passage to Texas. The New York Supreme Court held that the slaves were free. The appellate court affirmed. The Lemmons appealed.