Is there a use for finished resources other than trade?

[Crazy Dinosaur]

After turning cotton into cloth, sugar into rum, etc. do I have any reason to keep them in my settlements, or are they specifically to be sold/traded?

 

[Tinkerbell]

no use, just sell 'm.

 

[r_rolo1]

That is... besides guns ( and tools too )

 

[Buligo]

I know what you mean: in Imperialism II Age of Exploration there you had means to use the stuff you produced, like paper for new colonists,lumber too, coal for making steamships etc. Not so in CivCol. Waah. To bad.
All in all, it seems that the game is set in a way that it is strongly advised to build, conquer and reach end-game content in the least rerasonable amount of time. After the WoI is over, it's really over. Pity.