The modern country is a federal union of several different states.  The name is taken from a kingdom which flourished 1000 years ago a few hundred miles to the west.  The population is ethnically diverse, which fact has been a source of tension.
     At the time of the appearance of the Europeans along the Gold Coast the dominant political power was Ashanti.  This was a rich, war loving feudal kingdom.  In the 17th century Ashanti began to sell slaves to the British, and in the next 200 years they became the major source in the region.  The British set up permanent settlements on the coast.  These gradually grew inland.
     As the slave trade began to wind down in the 19th century and the British began to think more in terms of mining and agriculture, the Ashanti found themselves fighting several wars with the British.  They won all except the last one, and ended up as a colony.
     The top end of the pre-colonial economy was slaves, and wherever there are slaves and boats there's gold, weapons, and liquor.  The gold traded by weight in the form of dust.  The weight was portioned in "tackoes," which are little peas, black on one side and red on the other.  12 tackoes made an "ackey," and 16 (later 18) ackeys made a troy ounce.
     Other major trade items were cowries, copper and iron in rods, rings, wire, and ingots, beads, cloth, and salt. The great (and retired) primitive money dealer Paul Dillingham brought back a bag of tackoes from one of his West African trips, as well as numerous other tradable items from Ghana.  Nothing much else in the way of numismatica primitiva Ghanaiana has been seen for at least a decade.
     The British Gold Coast Company essayed 2 coin issues.  The first, in 1796, is pretty darn scarce.  Someone once told me a fish story about buying a little hoard of copper proof quarter ackeys in San Jose in the mid-80s.  Said he got them for $12.50 each and doubled his money!  (Like, let me tell you about the Athenian dekadrachm I got out of a 25¢ junk box when I was a kid...)  Anyway, that is the "common" denomination, which means you do actually see it occasionally.  And I don't recall seeing these coins in low grade, but I may be wrong.  They are hardly ever offered.
     1818 coins are a lot easier to come by.  Proof seems to be the way they usually show up, but actually what I mean is proof-AU, because they usually have some minor problem or other.  The 1818 half ackey is about ten times easier to find than the full ackey.  Low grades are not much in evidence.
     In the first half of the 20th century the circulation in the Gold Coast Colony was handled by the British West African Currency Board.  Specific to the Gold Coast in this period is a small series of advertising medallets in aluminum promoting the use of cocoa.  These things come in all grades from "corroded" to XF, and typically cost between $5.00 and $25.00.
     Ghana became independent in 1957, the first of the conquered African territories to be "decolonized."  A republic was established in 1960 with Kwame Nkrumah as President.  Nkrumah was a progressive socialist who concentrated on education, health, and infrastructure development.  Unfortunately he also cultivated an expensive  Mao-style personality cult, allowed corruption to flourish, and badly mismanaged the economy.
     Nkrumah's coins were issued from 1958 to 1965.  The 1958 coins are common in both Unc and proof.  The proofs were originally issued loose in plush cases, so a lot of them are a bit impaired.  Uncirculated circulation coins tend to be a trifle scarce these days, but only in relation to their former ubiquity.
     A gold thing was issued in 1960 which used to be listed as a "2 pound" coin.  Now the consensus is that it should be called a medal.  It's not too hard to find.
     In 1965 the old British denominations were thrown out in favor of pesewas and cedis, cedi being a local name for the cowrie shell which served commerce in olden days.  Nkrumah managed to get his face on these coins just before he was overthrown.  These last Nkrumah circulation coins are a little hard to find, and by rights ought to be worth more than their listings.  Similarly with the OAU conference things.  I find them a bit difficult.  Can't just go out and buy a handful like you can the 1958 crowns.
     In the post-Nkrumah period a set of bronze and copper-nickel pesewa coins was issued from 1967 to 1979.  These are not easy to find.  Their prices are set so low that dealers never bothered to import them.  The 10 pesewa often shows up in poundage.  This is because its dimensions approximate a US quarter and people try to use them in vending machines and parking meters.
     In 1979 the coinage began to reflect ongoing inflation.  Brass 50p and 1 cedi were issued.  These were succeeded by even more inflated coins, including multiple cedi denominations, in 1984 and 1991.  Once again, there seems to be no serious wholesale of these coins, and once again I'm sure that the low catalog values have had something to do with their relative unavailability.
     And true to form, I have found the various commemoratives issued since 1981 are also difficult.  I can pick out numerous coins from out of the way places like Seychelles or Mauritius or even Mauritania which are relatively easy to come by.  But who has these Ghanaian commemoratives?  I just don't see them.  Do you?