They are manufatured by AYP (American Yard Products) which has long been owned by Electrolux and is now part of EHP (Electrolux Home Products) which also includes Husqvarna, Poulan, WeedEater, McCulloch, Partner, Target, etc. It is now managed by Husqvarna.
Honda
John Deere makes their own lawn tractors(mowers) in Horicon, Wisconsin, USA.
Husqvarna
John Deere manufactures their own products
Cub cadet is a division of international harvester.
there have been a few. the mostcomman is AYP
American Yard Products. They also make Husqvarna and a few others.
They are made by MTD. I've been told that it is Polan Pro riding mower with an "upgraded" Honda engine.
Because sears tractors are JUNK. They don't last but about on the average 7 years. I know a repair service in my hometown who services a huge selection of lawn tractors and ex[plained to me about how the tractors are not made very well. Most generally it is about the transmission.
Big box hardware stores often carry lawn garden tractors from big name companies. Home Depot carries John Deere and Ariens brand tractors. Sears carries Craftsman brand tractors. You could also try a local feed store or check the craiglist ads for used models.
2001 was the last year of production of lawn tractors.
You have to decide first whether or not you would like to purchase a new lawn tractor or a used one. For a new one, Sears is a good bet. For a used one, I would advise you to check on ebay.