This review assesses sociological and historical research relevant to
the emergence and consolidation of the American middle class in the ni
neteenth century. On the one hand, macrosociological theories have rel
ied on a two-class model which renders the middle class a residual soc
ial category. Yet, on the other hand, community studies of the ''new''
social history-while they have opened up new avenues of inquiry into
the complex social processes underlying middle class formation-have te
nded to focus on particular decades of the nineteenth century, leading
to a fragmented view of the occupational composition of the middle cl
ass. Distinct literatures have developed around the study of particula
r occupational strata: artisans, small capitalists, white-collar wage
earners, and the petite bourgeoisie. We argue here that different occu
pational groups overlap in time and represent a heterogeneous and hist
orically shifting middle class rather than distinct entities. The argu
ment for the integrity of a distinct middle class also rests on an und
erstanding of the development of urban institutions and the cultural e
xpressions of middle-class lifestyles and behavior. The expansion of t
his middle class, however, was closely linked to a growing economy and
increasing equality of opportunity. We speculate that the reversal of
these conditions, evident from the 1970s, may undermine the well-bein
g of the middle class and its correlative social values, notably toler
ance and civility.