The US one cent used to be much larger, but the size was reduced in 1857.
The penny coin which was worth a cent
Penny
Penny.
penny
penny
The US coin looks very much like a modern US penny
The first US wheat penny minted was the regular 1909.
Such a coin was not made by the US Government.
The Penny is used the most in the US.
No US one cent coin struck in Philadelphia has ever had a "P" Mintmark so the coin is just a penny.
No. No genuine US coin other than the 1943 steel penny will stick to a magnet. If you have a US coin that sticks to a magnet other than the steel penny, it is a counterfeit.
A US "penny" is actually a 1 cent coin, worth 1/100 of a dollar. A British penny (the coin's official name) is worth 1/100 of a pound sterling.