By 1860, the settlement of the American West along with timber shortages in the East converged with ever-widening impact on the pine forests of the Great Lakes states.
Here's what I think: In this sentence, the intersection of the settlement and timber shortages leads to the ever-widening impact on that forest. But literally, I would take it this way: The settlement together with the shortage converged with the increasing impact. However, it doesn't make sense this way, because it means that the settlement with the shortage is getting closer with the increasing impact.
How to understand the meaning of CONVERGED WITH in this sentence?