You will owe tax on the capital gain which is $1 ($3-$2).
Since you held the asset for more than a year the gain is long term capital gain.
Long term capital gain is taxed upto a maximum tax rate of 15%.
For 2011 and 2012, long-term capital gains (assets held for more than one year) are taxed at a maximum tax rate of 15% (unless you are selling collectibles or have depreciation recapture on real estate, then the maximum rate is 28% and 25% respectively).
So, your other income is low and you fall in 10-15% tax bracket than you will pay 0% tax on long term capital gain.
But if your income is high and you are in higher tax bracket than you pay 15% tax on gain.
will I have to pay maryland state taxes on top of the 15%?