Probably not

But look at how other colonies have flourished like Canada and Australia and New Zealand, Hong Kong , Singapore

The British did a good job with most colonies in setting them up for autonomy and success.

Regarding USA, if we remained a colony with representation and autonomy, maybe USA would have been better off.

Tough to say because USA became economic superpower after the civil war. By 1898 USA had surpassed Great Britain has the largest economy in the world