Quick google on "tomahawk history" gave this not very scholarly piece but probably OK in the basics.
The History of Native American Tribes. Tomahawk ShieldHistory of the Tomahawk
"Perhaps the most ubiquitous symbol associated with Native Americans is the tomahawk. However, few people are aware of the multiformity of its history as well as its physical characteristics.
The term "tomahawk" is a derivation of the Algonquian words "tamahak" or "tamahakan". The earliest definitions of these words (early 1600's) applied to stone-headed implements used as tools and weapons. Subsequent references involved all manner of striking weapons; wood clubs, stone-headed axes, metal trade hatchets, etc. As the years passed a tomahawk was thought of as any Indian-owned hatchet-type instrument. That association changed somewhat as white frontiersmen (traders, trappers, explorers) came to rely on the tomahawk as standard equipment.
The popular perception of a tomahawk has become that of a lightweight (one lb. or less) metal head on a wood handle. With the exception of a relative few made by Indian blacksmiths, tomahawks were manufactured on a large scale in Europe or created by individual makers in America. Some were crafted in a most elaborate manner, with fancy engraving and pewter or silver inlaid blades and handles, for presentation to important chiefs in order to commemorate treaties and seal friendships. The majority of them, though, were personalized by their owners. Vastly different methods or adornment abounded - according to materials available and the customs and styles of the time and region. Hafts were polished smooth, carved, scalloped, inlaid, branded with hot files, tacked, wrapped with copper or brass wire, covered with rawhide, leather or cloth, stained, painted and hung with every type of ornament imaginable.
Metals used (in rough chronological order) were solid iron, iron with a welded steel bit (cutting edge), brass with steel bit and lastly, solid brass (which diminished its usefulness as a wood-chopping tool). The end of the head opposite the cutting edge provided a place for a spike, hammer poll, or most ingeniously, a pipe bowl.
With a smoking pipe bowl and a drilled or hollowed handle, the pipe tomahawk became the most popular "hawk" of them all. It developed as a trade good by Euro-Americans for trade with native peoples. Iroquois men traded furs for these sought-after tomahawks. Ornate examples were presented at treaty signings as diplomatic gifts to Indian leaders, who carried them as a sign of their prestige. It was at once a weapon and symbol of peace for over 200 years and was carried, scepter-like, in the majority of photographic portraits of prominent Indian chiefs."
Source: "Tools and Weaponry of the Frontiersman
and Indian" by Ray Louis
The History of Native American Tribes. Tomahawk "Tomahawk was a small ax that the Indians of North America used as a tool and a weapon. Most tomahawks measured less than 18 inches (45 centimeters) long and were light enough to be used with one hand. Early tomahawks consisted of a head (top part) made of stone or bone mounted on a wooden handle. Some tomahawks ended in a ball or knob instead of a flat blade. After Europeans arrived in America, the Indians traded with them for iron tomahawk heads.
The Indians used tomahawks to chop wood, to drive stakes into the ground, and for many other purposes. In battle, warriors used their tomahawks as clubs or threw them at their enemies. Tomahawks also served as hunting weapons.
The Indians used a pipe tomahawk in religious ceremonies. This kind of tomahawk had a pipe bowl on the head and a hollow handle, and it could be smoked as a ceremonial pipe. The Indians decorated these tomahawks with feathers or dyed porcupine quills.
Some people think the expression bury the hatchet came from an Indian custom of burying a tomahawk to pledge peace. However, many scholars doubt that the Indians ever had such a custom."