US Postage Due Philatelic Sales

How were US postage stamps sold to collectors and how were they priced? Thanks!

First day Ceremony 1959 at TOPEX'59 on June 19, 1959 front



First day Ceremony 1959 at TOPEX'59 on June 19, 1959 inside



First day Ceremony 1959 at TOPEX'59 on June 19, 1959 back

The final postage due series was issued at TOPEX'59 and postage due stamps were sold freely at the show (I wasn't there being only 1 year old at the time). After that they were sold at the Philatelic Sales Division (I have one of the order blanks from 1962 showing the 1/2 cent to the 5 dollar postage dues).

To get a plate block you has to buy a strip of 20 up the 50 cent. The 1 and 5 dollar you only had to buy a block of 4 to get a plate block. Then in 1974 (I remember this well) you could buy them over the counter at you local post office which I did until 1986 when the Post Office withdrew them (they didn't even have them at the philatelic window at the international show in Chicago which was the first place I went when the show opened).

They were always sold at face value, and of course, you couldn't use them as postage.