WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<RESTATED>
<CIK> 0001057920
<NAME> NUVEEN TAX-FREE UNIT TRUST
<SERIES> Series 1001
<NAME> NEW YORK INSURED TRUST
<NUMBER> 280
<MULTIPLIER> 1
<CURRENCY> U.S. DOLLARS
<FISCAL-YEAR-END> APR-30-2000
<PERIOD-START> MAY-01-1999
<PERIOD-END> APR-30-2000
<PERIOD-TYPE> YEAR
<EXCHANGE-RATE> 1
<INVESTMENTS-AT-COST> 1,120,855
<INVESTMENTS-AT-VALUE> 1,015,886
<RECEIVABLES> 21,505
<ASSETS-OTHER> 0
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 1,038,905
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 32,951
<TOTAL-LIABILITIES> 32,951
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 0
<SHARES-COMMON-STOCK> 11,554
<SHARES-COMMON-PRIOR> 14,165
<ACCUMULATED-NII-CURRENT> 8,667
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> -25,654
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> -104,969
<NET-ASSETS> 1,005,954
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 63,303
<OTHER-INCOME> 0
<EXPENSES-NET> 3,575
<NET-INVESTMENT-INCOME> 59,728
<REALIZED-GAINS-CURRENT> -25,800
<APPREC-INCREASE-CURRENT> -110,760
<NET-CHANGE-FROM-OPS> -76,832
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 65,838
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 17,500
<NUMBER-OF-SHARES-REDEEMED> 5,946
<SHARES-REINVESTED> 0
<NET-CHANGE-IN-ASSETS> -366,911
<ACCUMULATED-NII-PRIOR> 14,777
<ACCUMULATED-GAINS-PRIOR> 146
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 0
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 0
<AVERAGE-NET-ASSETS> 0
<PER-SHARE-NAV-BEGIN> 0
<PER-SHARE-NII> 0
<PER-SHARE-GAIN-APPREC> 0
<PER-SHARE-DIVIDEND> 0
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 0
<EXPENSE-RATIO> 0
[AVG-DEBT-OUTSTANDING] 0
[AVG-DEBT-PER-SHARE] 0
</TABLE>