Oldest sons in the early modern or modern era may have inherited the family farm, but except perhaps in very rich families,  younger sons left home, emigrating or going west or north to homestead, joining the army or navy or even becoming foreign mercenaries, or finding work in cities or on the estates of rich landlords.  You really have to go back to the middle ages----or eastern Europe---with peasant agriculture and serfdom to find everyone living together----and working for the lord.