WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<RESTATED>
<CIK> 0000860940
<NAME> NUVEEN TAX-FREE UNIT TRUST
<SERIES> Series 609
<NAME> NATIONAL TRADITIONAL TRUST
<NUMBER> 498
<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> 6,595,978
<INVESTMENTS-AT-VALUE> 6,972,895
<RECEIVABLES> 182,946
<ASSETS-OTHER> 59,207
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 7,215,048
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 1,808
<TOTAL-LIABILITIES> 1,808
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 0
<SHARES-COMMON-STOCK> 78,211
<SHARES-COMMON-PRIOR> 82,539
<ACCUMULATED-NII-CURRENT> 102,192
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 157,674
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 376,917
<NET-ASSETS> 7,213,240
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 549,700
<OTHER-INCOME> 0
<EXPENSES-NET> 10,661
<NET-INVESTMENT-INCOME> 539,039
<REALIZED-GAINS-CURRENT> 9,886
<APPREC-INCREASE-CURRENT> -278,701
<NET-CHANGE-FROM-OPS> 270,224
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 621,388
<DISTRIBUTIONS-OF-GAINS> 720,876
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 100,000
<NUMBER-OF-SHARES-REDEEMED> 21,789
<SHARES-REINVESTED> 0
<NET-CHANGE-IN-ASSETS> -1,491,244
<ACCUMULATED-NII-PRIOR> 184,541
<ACCUMULATED-GAINS-PRIOR> 147,788
<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>
