Ninian Edwards caused trouble for himself when he wrote several articles in the "Washington Republican" under the pseudonym "A.B." that attacked U.S. Treasury Secretary William H. Crawford. Edwards alleged that Crawford had known of the impending failure of Illinois' Bank of Edwardsville in 1821, but had not withdrawn federal money from it. Edwards found that none of Crawford's rivals was willing to support his charges, and he was unable to produce corroborating evidence. He resigned his Senate seat on March 4, 1824, to take a job he wanted as the first United States Minister to Mexico. While en route to his new position, Edwards was called back to Washington to testify before a special House committee concerning the "A.B. Plot". Unable to substantiate his claims, Edwards resigned his diplomatic post, to be replaced by Joel Roberts Poinsett.