The last one (white) looks to be a leghorn.
The second to last one looks smaller than the white leghorn (assuming they are the same age) maybe a OEGB or (if younger than the white leghorn) maybe a brown leghorn or a welsummer.
Uncertain about the first one (first two pics).
OEGB is an Old English Game Bird. As chicks the OEGB looks very similar to a brown leghorn, if not identical, except size.
I think in all likelyhood that you have a brown leghorn. OEGB are very small about 1/3 the size of a brown leghorn. OEGB are smaller than most bantams.