Historians believe that coins were introduced in India sometime around the 5th and 6th centuries BC to facilitate trade. The earliest coins were silver and punch-marked with various symbols of animals, plants, and humans.
Coins came into use about the same time in Asia minor (present-day Turkey) and in China.
No. For one thing the Roman were not the only ancient people who issued coins. In fact when they introduced their coins, which was quite late, they copied the Greek's use of coinage. Moreover, coins have been used ever since by the many states of Europe. Having coins (and banknotes, since they were introduced) is part of the monetary economy. The US introduced coins because it had a monetary economy. The Americans were using coins before independence. They used British coins. When they became independent, it was only natural that they issued their own coins.
a large scale economy
Check that coin again. The Carson City Mint didn't begin producing coins until 1870, and the trade dollar wasn't introduced until 1873.
kushans
In ancient times, coins were made from brass, copper, silver, and gold. The use of nickel was not introduced until modern times.
Coins.
use of standardized metal coins
Indus valley civilization according to history tells about that India is the first country to issue coins for trading.
Yes, but it's a Trade Dollar intended for use in international commerce. Trade dollars differ in size and weight from the more-familiar Morgan dollars that were introduced that year. There's more information about prices at the Related Question.
no