I want to cut a 1.5" deep 1/4" mortise using a router. I didn't have a
bit long enough so I rooted through my catalog collection and ordered a
Freud bit that was 2.875" long with 1" of carbide.

It arrived yesterday and although it has a 1/4" shank, there appears to
be a section just above the carbide that is thicker than 1/4". Even if
that's an optical illusion, the package says I should only cut 1" deep
(the length of the carbide) with it.

I didn't see any other bits that were even that long.

How do you cut 1.5" mortises with a router? Or should I just give up
and use some other method?

Up to now I have cut mortises on the drill press or by hand. But this
project (an entertainment center) is going to require about 100 so I
thought I'd try the router with a jig.

And no, I can't afford a dedicated mortising machine :-).

--
Homo sapiens is a goal, not a description