On this Picostat.com statistics page, you will find information about the SP500close data set which pertains to Closing Numbers for S and P 500 Index. The SP500close data set is found in the DAAG R package. Try to load the SP500close data set in R by issuing the following command at the console data("SP500close"). This may load the data into a variable called SP500close. If R says the SP500close data set is not found, you can try installing the package by issuing this command install.packages("DAAG") and then attempt to reload the data with library("DAAG") followed by data("SP500close"). Perhaps strangley, if R gives you no output after entering a command, it means the command succeeded. If it succeeded you can see the data by typing SP500close at the command-line which should display the entire dataset.
If you need to download R, you can go to the R project website. You can download a CSV (comma separated values) version of the SP500close R data set. The size of this file is about 39,027 bytes.
Closing Numbers for S and P 500 Index
Closing numbers for S and P 500 Index, Jan. 1, 1990 through
Derived from SP500 in the MASS library.
Dataset imported from https://www.r-project.org.