Can anyone tell me anything about these stamps-pics added

coinandcurrency242

I am not much of a stamp collector but I have some stamps laying around. Any info would be great.

US stamps:
A 6 cent US stamp with the Flag on a pole and the White House behind it.
A 15 cent stamp with Oliver Wendell Holmes?
2 20 cent stamps with the flag on a pole and a lady sitting in from of a building?

Canada stamps:
The candian flag and mountains and sky in background.
A 20 cent Canada stamp with needles and cones.
A 30 cent stamp with a ladies portait.
A 30 cent stamp with Terry Fox?

pics are at stamps

Any help would be great

Thanks Brent

buster75633

coinandcurrency242
Based on your scans all the US stamps appear to be coil stamps so I based my references on that.
6c Flag over White House is Scotts#1338a issued in 1969.There were five issues of this stamp only two were coil,the other being Scotts#1338g issued in 1971 and it was 8c.
20c Flag & Supreme Court Scotts#1894 issued 1981
15c Oliver Wendell HolmesOriginally issued from 1965-1978 in sheets as Part of Prominent Americans Series.The one you have appears to be a coil stamp.Either Scotts#1305E issued 1978 or 1305Ei issued 1979.
I do not know what the difference is,but apparently two different dies were used.
I do not know what the value is,but probably just a few cents in used.
Do not know anything about the Canadian stamps.
Hope this helps
buster75633