<TABLE> <S> <C>
<PAGE>
<ARTICLE> 9
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM CORNERSTONE
BANCORP INC. AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL
STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> DEC-31-2000
<PERIOD-START> JAN-01-2000
<PERIOD-END> JUN-30-2000
<CASH> 8,626
<INT-BEARING-DEPOSITS> 133
<FED-FUNDS-SOLD> 7,196
<TRADING-ASSETS> 0
<INVESTMENTS-HELD-FOR-SALE> 24,322
<INVESTMENTS-CARRYING> 15,727
<INVESTMENTS-MARKET> 15,321
<LOANS> 93,329
<ALLOWANCE> 1,800
<TOTAL-ASSETS> 153,793
<DEPOSITS> 127,561
<SHORT-TERM> 10,079
<LIABILITIES-OTHER> 748
<LONG-TERM> 0
0
0
<COMMON> 11
<OTHER-SE> 15,394
<TOTAL-LIABILITIES-AND-EQUITY> 15,405
<INTEREST-LOAN> 3,942
<INTEREST-INVEST> 1,266
<INTEREST-OTHER> 179
<INTEREST-TOTAL> 5,387
<INTEREST-DEPOSIT> 1,572
<INTEREST-EXPENSE> 1,743
<INTEREST-INCOME-NET> 3,644
<LOAN-LOSSES> 143
<SECURITIES-GAINS> (14)
<EXPENSE-OTHER> 2,457
<INCOME-PRETAX> 1,396
<INCOME-PRE-EXTRAORDINARY> 833
<EXTRAORDINARY> 0
<CHANGES> 0
<NET-INCOME> 833
<EPS-BASIC> 0.76
<EPS-DILUTED> 0.75
<YIELD-ACTUAL> 5.46
<LOANS-NON> 1,150
<LOANS-PAST> 4
<LOANS-TROUBLED> 0
<LOANS-PROBLEM> 0
<ALLOWANCE-OPEN> 1,626
<CHARGE-OFFS> 10
<RECOVERIES> 41
<ALLOWANCE-CLOSE> 1,800
<ALLOWANCE-DOMESTIC> 1,800
<ALLOWANCE-FOREIGN> 0
<ALLOWANCE-UNALLOCATED> 0
</TABLE>