This German map from 1850 seems to spell it "Monterey", although it's a little hard to make out. https://history.utah.gov/wp-content/uploads/2018/07/Radefeld-N

This German map from 1850 seems to spell it "Monterey", although it's a little hard to make out. https://history.utah.gov/wp-content/uploads/2018/07/Radefeld-Neueste-Karte-Mexico-full.jpg https://history.utah.gov/wp-content/uploads/2018/07/Radefeld... This American map published at the time of the Mexican-American war labels it "Monterey B." https://history.utah.gov/wp-content/uploads/2018/07/Mitchell-Oregon-and-Upper-California-full-1200x1451.jpg https://history.utah.gov/wp-content/uploads/2018/07/Mitchell... This American map published before the war also labels it "Monterey B." https://mapgeeks.org/wp-content/uploads/1845-Map-of-California.jpg https://mapgeeks.org/wp-content/uploads/1845-Map-of-Californ... Here's a map produced by a British cartographer showing the spelling to be "Puerto de Monterey" in 1745: https://en.wikipedia.org/wiki/History_of_California#/media/File:Map_of_California_as_an_island_R.W._Seale_1745.jpg https://en.wikipedia.org/wiki/History_of_California#/media/F... This 1650 Dutch map seems to spell it "Monterey", although the handwriting is archaic and a little bit difficult to interpret: https://www.wdl.org/en/item/2661/view/1/1/ https://www.wdl.org/en/item/2661/view/1/1/ Perhaps most convincingly, this Spanish map published in Madrid in 1802 documents a 1603 expedition, one of the first to navigate the California coast. It uses the spelling "Puerto de Monte Rey". https://digitalcommons.csumb.edu/hornbeck_spa_1_a/22/ https://digitalcommons.csumb.edu/hornbeck_spa_1_a/22/ None of which is to say that the "Monterrey" spelling wasn't used. The following English-language map from 1838 uses the "proper" Spanish spelling: https://upload.wikimedia.org/wikipedia/commons/a/ac/California1838.jpg https://upload.wikimedia.org/wikipedia/commons/a/ac/Californ... I'm sure there are plenty of other examples using a spelling of "Monterrey" as well.