to growth, Rome’s demand for taxes from the provinces may
have meant that provincial economies were obligated to grow
or suff er. Regardless, growth remained gentle and regionally
distinctive in the fi rst two centuries c.e.
Toward the end of the empire, both change and continu-
ity were represented. Infl ation led to attempts at price control
by the Roman emperor Diocletian, and changes were made to
the taxation system, but the volume of trade remained strong.
Aft er the fall of the Western Roman Empire, goods were ex-
changed and peoples were transported at much lower rates,
with lesser degrees of sophistication, and without the levels
of central control that had characterized the Imperial Period.
In the sixth century c.e. some 5,000 cargo ships sailed in the
eastern Mediterranean, indicating both the continued signif-
icance of trade and exchange and the considerably greater ac-
tivity during the Roman Empire across the Mediterranean.THE AMERICAS
BY J. J. GEORGE
Tra d e is typically defi ned as a two-way exchange—the busi-
ness of buying, selling, or bartering commodities—motivated
by profi t or need. In a true market system, trade would be
at least partially divorced from social or political entangle-
ments, and the value of the commodities would follow laws of
supply and demand, unencumbered by legislation. Trading
activities in the Americas, however, were varied and complex,
sometimes encumbered with political and social obligations
and sometimes more freewheeling.
Generally, archaeologists consider the presence of nonlo-
ca l objects at a site to be ev idence of trade, a lt hough ot her sys-
tems of exchange existed, including reciprocity and tribute.
Reciprocity implies a mutual exchange of privileges or goods,
oft en with socially acceptable gift s exchanged on a roughly
equal basis with the aim of establishing or solidifying social
or political relationships. Tribute, on the other hand, was of-
ten a one-way exchange between a dominant overlord and a
subject polity. Th e later Aztec Empire (15th and 16th centu-
ries) provides the primary Mesoamerican model of tribute
exchange: Conquered territories were forced to contribute
substantial amounts of prized goods in return for assurance
that they would not be decimated. Exchange in its broad-
est sense also included the fl ow of art styles, religion, ritual,
ideas, and technology as part of cultural diff usion. Although
this form of exchange was oft en unidirectional and fl owed
from the impulses of empire, expansion, and diff usion, it also
could be a shared enterprise and a means by which disparate
political and social entities were united.
Mesoamerican cultures relied almost entirely on human
carriers to transport goods, limiting the range for perishable
commodities and resulting in high transportation costs. Th e
wheel was a known concept, but there is no evidence yet of its
use in transportation. Transport of items such as foodstuff s
was limited geographically and reinforced localized trade in
those items. Longer-distance trade emphasized high-value,low-weight luxury goods oft en classifi ed as elite items. In
turn, the people who controlled trade and trade routes oft en
solidifi ed elite status or rulership roles for themselves.
Common Mesoamerican trade items included ceramics,
lithic material such as obsidian and chert, textiles, perish-
able tropical goods, precious stones, metals, and foodstuff s.
During Mesoamerica’s Formative or Preclassic Period (ca.
1800 b.c.e.–ca. 150 c.e.) chiefdoms at several sites—such as
Olmec sites on the Gulf Coast, sites in the Valley of Oaxaca
and Chalcatzingo in Morelos, and several sites in Chiapas—
exchanged items like jadeite, obsidian tools, ceramic vessels,
shell ornaments, and animal products. Obsidian is a particu-
larly useful material to document trade systems because the
absence of metal tools meant it was used extensively in tool-
making and thus was highly valued. Additionally, obsidian
has few sources, and its trace element composition is distinct,
making chemical sourcing possible and allowing research-
ers to track its distribution. Major obsidian sources include
Pachuca in central Mexico and El Chayal and Ixtepeque in
highland Guatemala. Obsidian from these sources was found
throughout Mesoamerica.
Other examples of trade items include high-quality
chert from Belize, used to make tools throughout the Ma-
yan lowlands of northern Guatemala and Mexico’s Yucatán
Peninsula. Basalt, andesite, and granite were used to make
grinding tools such as mortars and pestles; such volcanic
material was unavailable locally to people in the Mayan low-
lands and was transported in from the highlands. Textiles,
a highly valued but perishable item, were also traded. Al-
though few survive, especially from the dense, tropical low-
lands, the tools from which they were made, such as spindle
whorls, fi rst show up along the Gulf Coast and later through-
out Mesoamerica, suggesting some system of diff usion
through trade. Perishable goods like precious feathers from
the quetzal bird of Guatemala and jaguar pelts—both sym-
bols of royalty—were distributed throughout Mesoamerica.
Precious stones, whose value in part derives from limited
natural distribution, rarity, and symbolic importance, were
used to make fi ne jewelry. Jadeite from Costa Rica and Gua-
temala and turquoise from the southwestern North America
found wide distribution throughout Mesoamerica, as evi-
denced in various grave caches. Foodstuff s were limited lo-
cally in most periods, although empires such as Teotihuacán
(ca. 100–700 c.e.), had infrastructures substantial enough to
obtain grains, maize, beans, and amaranth as tribute from
greater distances.
Many North American societies up to and beyond 500
c.e. were of the hunter-gatherer type, which makes data dif-
fi cult to obtain. Various forms of trade were known. One
example is from the fi rst millennium c.e., which was a kind
of golden age for the Arctic Eskimo, an era that saw bril-
liant creativity in both arts and manufacturing, and the
perfection of skills and equipment required to hunt diverse
northern animals. Th ese developments originated along the
shores of the Bering Sea and the Bering Strait and spreadtrade and exchange: The Americas 11070895-1194_Soc&Culturev4(s-z).i1107 1107 10/10/07 2:31:06 PM