There were several Marquesados of Montealegre, including one established in 1737 in Peru. This dress was out of style, even in the colonies, by 1737.
From Pinterest search. Also posted to the Iberian Dress in the Louis XIII and XIV Eras Album here.
Space had to be allocated for the brocade and lace on a ship going halfway around the world through the dangerous Straight of Magellan for this dress.
Keywords: straight coiffure, jeweled floral hair ornaments, earrings, necklace, fitted bodice, straight neckline, lace bertha, brooch, three quarter length close upper sleeves, long puffed virago lower sleeves, lace back-flared cuffs, bracelets, full skirt, fan