Breastfeeding, in spite of proven benefits and energetic promotion, lags behind national goals, is less prevalent in disadvantaged populations, and declines across successive children in a family. Using longitudinally linked data from the New Jersey Electronic Birth Certificate (EBC) from 1996 to 2001, we found considerable fluidity in breastfeeding status at hospital discharge for births to the same mother. Among mothers who breastfed exclusively after the first birth, only 69% did so after the second (we refer to this as recurrence). Among mothers who exclusively formula fed after the first birth, 16% initiated exclusive breastfeeding after the second birth (referred to as recruitment). Combination feeding the first born, i.e., breastfeeding supplemented by formula, was followed by exclusive breastfeeding for 38% of second births. Rates of recurrence and recruitment differed in distinct ways by race/ethnicity and immigrant status. We conclude that breastfeeding initiation is not necessarily or exclusively a matter of fixed preferences, and that opportunities exist to expand breastfeeding to realize national goals by enhancing both recurrence and recruitment.