To recruit cowboys you can either use the menu at the Hotel building next to your Saloon,
or you recruit them via the menu on the left.
To choose the quantity of your new units you can use the slider or the input field. Now simply click on “recruit” to start the process.
The little digit on the right of the cowboy-button will show you the current number of units you have available. A red colored digit means that you haven’t reached your unit limit yet and can still recruit some more. To raise the limit, simply expand the Hotel building.