How to access objects in R workspace by position?

I'm certain the answer is goingt to be very simple. Assume I have a number of data frames in my workspace, from a function that reads in a large number of files.

for(i in 1:10) {
    df <- data.frame(matrix(1, nrow=10, ncol=20))
    assign(paste0("df", i), df)
    rm(list=c("df", "i"))
    }

How can I access the data frame (or an object) by the position in the workspace as opposed to its name?

For example, assume I wanted to make a copy of the first object in my workspace. I can identify the object by ls()[1]. But, how could I extend that to actually access the data frame. Of course, temp <- ls()[1] doesn't work. Any help in pointing out the obvious would be helpful!