I agree with Red... exhibiting at a show is the best way to go.
You can try getting in touch with a buyer of a major chain, but it won't be easy. Try sending samples, or even better, schedule an appointment. But keep in mind, buyers work on a calendar. They place orders months ahead of putting the product on the sales floor. They will probably have most of their buying dollars spent with major brands. Whatever is left over is called "open-to-buy." There will be fierce competition to get those dollars. Unless you have razor thin margins (so you can offer maximum profit to the retailer), you won't be given much of a chance. And be prepared to offer terms and have to buy back whatever doesn't sell after a specific period of time. Major retailers are notorious for taking forever to pay their invoices. So good luck...