In every public department, and upon all public works of the state, and of any county thereof, soldiers, sailors, guardians, marines and other members of the uniformed services who are veterans of any war of the United States, or of any military campaign for which a campaign ribbon shall have been awarded with a qualifying discharge as defined in RCW
73.04.005, and their widows or widowers, shall be preferred for appointment and employment. Age, loss of limb, or other physical impairment, which does not in fact incapacitate, shall not be deemed to disqualify them, provided they possess the capacity necessary to discharge the duties of the position involved: PROVIDED, That spouses of veterans with a qualifying discharge as defined in RCW
73.04.005 and who have a service connected permanent and total disability shall also be preferred for appointment and employment.