Learn English – Using “like” at the end of the sentence. North-East like

So now that I gave you the example does project onto here mean that person A feels the insecurity inside him and thinks that other people feel the same thing.

The meaning is more exactly the following:

• person A has a feeling of "insecurity inside of him"
• person A is denying that feeling
• person A is acting like others have the same insecurity that person A is feeling in reality (even though person A is denying he has those feelings).

It's useful here to remember that Herman Melville wrote in the 19th century. Language changes over time so what might have been a standard phrase at the time could be out of use now and sound very strange to us.

Currently, in the 21st century, we would normally say 'in the East', if we mean a place to the east of where we are. We also use 'the East' to refer to the East Coast of the U.S.A. I've noticed from reading other 19th century literature that it was more common in that time period to say something occurred 'at' a place, meaning the same thing as 'in' a place. My sense is that in this case 'the East' is a a proper name for the eastern part of the country, the same way we use it now. He is comparing the way business is done in two different places: 'along the Mississippi' and at 'the East', meaning on the East Coast of the country.