Already taken care of, thanks to help of “io_error” in the #wordpress IRC channel.
The basics of the solution are here:
https://www.viewfinderdesign.co.uk/archive/38/excluding-a-category-from-the-home-page/
I copied my index.php to home.php, and added the call to query_posts() he recommended, only instead of excluding a category (with the -catID), I only *included* the category I want to show on the front page (ie, “cat=1”).
Worked like a champ.