How do I import a feed from a wordpress site?

I believe I have AutoBlog setup properly according to the specifications. I wanted to be able to pull posts from an existing wordpress site not on the multisite network (through atom feed) that will help feed content to the sites on the multisite network using AutoBlog. I can make a new post on the site outside of the multisite network and AutoBlog will import that. However, AutoBlog doesn't import any of the older posts(they have featured images and video links). Is there something I am missing? I am currently developing the first site on the multisite network that will be duplicated eventually so it is important that I get this setup properly before other sites are deployed.