We were taught this in California in elementary school. Spanish colonial history actually tends to be taught at the same time or earlier than East Coast history in much of the American West (usually as "California" or "Texas" or "Colorado" history).
But they never taught us much about New Mexico.
I also don't know when you were in K-7 but knowing HN's age demographics probably the 1980s to early 1990s.
From the 2000s onwards, New Spain and Spanish rule was prominent.
Here are the snippets of the Texas History textbook from around the time I was in grade school in the 2000s [0][1][2]
[0] - https://worleytxhistory.weebly.com/uploads/8/7/9/6/8796216/c...
[1] - https://worleytxhistory.weebly.com/uploads/8/7/9/6/8796216/c...
[2] - https://worleytxhistory.weebly.com/uploads/8/7/9/6/8796216/c...
Then you moved on to US History where they briefly gave an overview of the 13 colonies forming the US (had to start somewhere), in which the great state of Texas is the largest within the contiguous US and pivots to all of Texas's great contributions and workings with the US. Re-visiting all the "alternative facts" learnt and filling in a lot of missing data has taken some time.