Copy using cp to include hidden files and hidden directories and their contents in Linux

cp -r /etc/. ~/etccopy

note the /. following /etc

After the command was ran - the hidden files in the subdirectories are present:

$ ls -a etccopy/skel/
.  ..  .bash_logout  .bashrc  .face  .face.icon  .profile

Alternative 1:

rsync -aP /etc/ ~/etccopy

Alternative 2:

cd /etc
find | cpio -pdumv ~/etccopy
cd -