Old dons playing golf with lead in American Gangster (9)

'american gangster' is the definition.
'goodfella' can be an answer for 'gangster' (goodfellas can mean gangsters). I am not certain of the 'american' bit.

'old dons playing golf with lead' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'dons' indicates putting letters inside (don means to wear or put on).
'playing' indicates anagramming the letters.
'with' means one lot of letters go next to another.
'golf'+'lead'='golflead'
'golflead' is an anagram of 'godfella'.
'o' put within 'godfella' is 'GOODFELLA'.

'in' acts as a link.

Can you help me to learn more?