If I am in the 15% tax bracket and I have less than $75,000 capital gains but TT shows that I owe income tax on it. How do I correct this?

your tax will depend on other factors, including other taxable income. TurboTax knows how to do the calculation.
Your capital gains must be Long Term gains (securities held more than one year) to obtain the favorable tax rates.

I did have long term capital gains.

Did you have other income as well?