US troops aid Laotians . Savannakhet , Vientiane : Uniformed United States military advisers instruct Royal Laotian soldiers in the assembling of a 75 mmm pack howitzer . Capt Clellan C Thrower , of Heflin , Alabama , is seen showing the connection of trail leg and wheel; on howitzer , while Lieut Col William B McFadyen , regional Adivser in this area , stands ar rear . United States troops in this area now wear uniforms at all times . 1 May 1961