Lucy Mack says that Oliver Cowdery taught school at the district school when the Smith family arrived in Harmony.
Lucy Mack Smith, History, 1845, 140-141, The Joseph Smith Papers website, accessed August 11, 2021
In a short time after our arrival from Harmony, a man by the name of Lyman Cowdery came into the neighborhood, and applied to Hyrum (as he was one of the Trustees) for the district school. A meeting of the trustees was called, and Mr. Cowdery was employed. But, on the day following, this Mr. Cowdery brought his brother, Oliver [Cowdery], to the trustees, and requested them to receive him instead of himself; for as circumstances had transpired which compelled him (Lyman) to disappoint them, or, that would not allow of his attending to the school; and he said, that he would warrant the good conduct of the school under his brother<’s> supervision. The [3 words illegible] trustees being satisfied with this arrangement, Oliver commenced his school; and came to our house to board. He had been in the school but a short time, when he began to hear concerning the plates from all quarters; as and as soon began to importune Mr. Smith upon the subject; but did not succeed in eliciting any information for considerable length of time: at last he gained my husband’s confidence so far as to obtain a sketch of the facts relative to the plates. On receiving this information he told Mr. Smith, that he was highly delighted with what he had heard; that he had been in a deep study upon the subject all day, and it was impressed upon his mind, that he should yet have the privilege of writing for Joseph; furthermore, that he had determined to pay him a visit at the close of the school, which he was then teaching.