More like the Union lost the civil war and retreated the Puerto Rico, which had just been acquired from Spain four years earlier. And then proceeded to institut

More like the Union lost the civil war and retreated the Puerto Rico, which had just been acquired from Spain four years earlier. And then proceeded to institute martial law and an aggressive Amerification campaign, stamping out Spanish language and local culture, before becoming a new democracy in the 90s that only retains the name USA as a technicality.