Programatically Changing Entry Types?
Something like this should work. I've also cleaned up the code a bit to be correct PHP syntax as my assumption is that you''ll be doing this in a module/plugin.

// Get all people entries
$entries = Entry::find()-&gt;section('people')-&gt;all();

foreach ($entries as $entry) {
    // If this was a "featured" historical person
    if ($entry-&gt;historical == 'featured') {
        // Change to featuredPeople entry type
        $entry-&gt;typeId = $featuredPeopleEntryTypeId;

        // Save entry
        Craft::$app-&gt;elements-&gt;saveElement($entry);
    }
}