What is referred to by 'a us president lbj'?

Based on the clue 'a us postal abbreviation mo', what is the answer? What is referred to by 'a us president usg'? What is associated with: a us president april 22 1994? What is referred to by 'a us president birchard'? What is associated with: a us stamp from 1965 commemorated the 700th anniversary of the birth of this italian poet? What is referred to by 'a us state capital'? What is referred to by 'a us state mt'? What is referred to by 'a us state th'?