NIST test vectors for RSASSA-PKCS1-V1_5-SIGN with the SHA-256 hash function? I haven't been able to find it on the web anywhere, and I need to check if my implementation of the algorithm is correct. Does NIST provide such a file?
A zip file of test vectors (FIPS 186-2 Algoithm Test Vectors for RSA) can be found at the bottom of the page on NIST's site pertaining to CAVP Testing: Digital Signatures.  

This file contains a readme and the test vectors for X9.31RSA,  RSA PKCS#1 Ver 1.5, and RSA PKCS#1 RSASSA-PSS signature generation. It looks like it does contain vectors for SHA-256.