Wrong leg color. Orps and marans are white leg. Rocks and wyandotte are yellow as are leghorns. If the chicks are straight comb, then likely buff Rock or buff leghorn. Egg color will clarify which. Rocks lay brown eggs.
Leghorns come in a variety of colors. These chicks are buff colored. Some of the breeds that have buff varieties are orpingtons, Plymouth rocks, wyandottes, Marans (they're called wheaten). Dunno if buff/wheaten leghorns exist or not.