If you want to access the actual file itself, just use your favorite text editor (I use emacs but you can use pluma of gedit or vimor whatever):

emacs ~/.bash_history

That is the default location if your history file. If you don't find anything there, you may have changed the history file's name. This is stored in the $HISTFILE variable, so print it out to check its current value:

echo $HISTFILE

If, instead of the file, you just want to see your history, you can run history as @minerz029 suggested. The history command with no options just prints the contents of your $HISTFILE followed by the commands executed in the current shell that have not yet been written to that file, with line numbers.