Despite no longer having the burden of his professorial and garden duties, by the late 1870s the burden of maintaining himself as the pillar of American botany prevented Gray from the progress he desired on "Synoptical Flora of North America", the follow-on to "Flora of North America". This burden consisted of the fact that other scientists often only accepted Gray's word on a botanical matter, and the number of incoming specimens to identify was increasing vastly: numbers had to be assigned to them, collectors needed to be corresponded with, and preliminary papers had to be published. By the early 1880s, Gray's home was the center of everything to do with botany in America. Every aspiring botanist came to see him, even if just to look at him through his window.