Octagon was a popular brand of bar laundry soap. However, it no longer being manufactured. It's expensive, but if you really need to own Octagon bar laundry soap, you can still purchase some here.
Fels-Naptha is still available and much cheaper so that could be an alternative. Here is a link on Amazon.
Fels Naptha Laundry Bar and Stain Remover, 5.5 Ounce (Affiliate Link)
