One of the trade show that I enjoy attending in the USA is the ASD show. I always attend the show in Las Vegas and found several new vendors for our e-commerce store. If you haven't heard about the show you need to check it out if you are looking for new manufactures that supply wholesalers with good gross margins. In the world of wholesale we all know it boils down to sales, gross margin and inventory turns.
My experience with looking for vendors in the USA if you go to Google you get a lot of people posing as supplies to wholesalers. The ASD show has importers that supply just wholesalers and don't compete with you at retail or wholesale. It is important to see the companies face-to-face and meet the owners and or managers.
I have been to China so many times to find vendors in the past. It is nice to be able to find supplies here in the USA and so close to where I live, (without the long flight) that are legit. There is also a section of the show that has international supplies as well for direct sourcing.
The Off Price Show is also in Las Vegas. This show is for close-outs and deals if you are the market for that. The Accessories Show is at the same time as the Office Price Show so that you can attend both at the same time.
You can get a list of the vendors that exhibit at these show on their respective websites, which I have put links in above. Happy vendor finding!