Why does egrep not find white space correctly in history listing?

Question

I have this in my command history:

  280  ls -l | egrep -v '^d'
  348  ls -l | egrep '^d'
  375  git help ls-tree
  376  git ls-tree
  377  git ls-tree HEAD
  378  git ls-tree HEAD^
  379  git ls-tree HEAD system
  380  git ls-tree HEAD system/
  381  git ls-tree HEAD^ system/
  460  ls
  463  ls
  464  ls /*
  465  ls */
  466  ls -d */
  468  ls -d */
  469  ls -d *

I can list all commands that end with / like this:

history | egrep "/$"

But if I want to list all commands that start with ls, and I type this:

history | egrep "^\s*\d*\s*ls"

It returns nothing.

However, if I the output the text to a file and copy the output to regex101.com, then this regex correctly finds all commands that start with ls.

Is there some other variable I need to use other than \s to identify whitespace in the output with egrep?