Tax Foundation: The High Burden of State and Federal Capital Gains Taxes:

As Congress begins to debate tax reform in the coming months, there is
one tax that they should pay close attention to: the capital gains tax.
The capital gains tax is a tax on profit through the sale of property or
investments. At the beginning of this year, the top marginal statutory
capital gains tax rate was increased to 23.8% from 15%.
Although lower than the tax on ordinary income, states also tax capital
gains, some of them as high as 13.3%, adding an additional tax
burden to savers and investors. Some taxpayers could pay up to a 33% tax on capital gains, a rate that far exceeds rates throughout
the world. This high tax rate has long-term negative implications for
the economy as people save and invest less and capital seeks higher
returns in other countries.

Long-term Capital Gains Rate
Rank	Country/State	Capital Gains Rate
1	Denmark	42.0%
2	California	33.0%
3	France	32.5%
4	Finland	32.0%
5	New York	31.4%
6	Oregon	31.0%
7	Delaware	30.4%
8	New Jersey	30.4%
9	Vermont	30.4%
10	Maryland	30.3%
11	Maine	30.1%
12	Ireland	30.0%
13	Sweden	30.0%
14	Idaho	29.7%
15	Minnesota	29.7%
16	North Carolina	29.7%
17	Iowa	29.6%
18	Hawaii	29.4%
19	District of Columbia	29.1%
20	Nebraska	29.1%
21	Connecticut	29.0%
22	West Virginia	28.9%
23	Ohio	28.7%
24	Georgia	28.6%
25	Kentucky	28.6%