Complex sentence: The burning of the Stanwix Station and others led to a significant delay to the Union advance, preventing the Fall of Tucson, Arizona's western Confederate capital, which housed one of two territorial courts; the other court was in Mesilla.
Split into simpler sentences: The burning of the Stanwix Station and others led to a significant delay to the Union advance. Preventing the Fall of Tucson, Arizona's western Confederate capital as is housed one of two territorial courts, the other court was in Mesilla.