Complex sentence: If born a slave, it is currently unknown how he received his freedom; however, it is known that he was not freed by the Washington D.C. Emancipation Act as no Emancipation Petition was filed.
Split into simpler sentences: If born a slave, it is unknown how he received his freedom; however, he was not freed by the Washington. D.C., Emancipation Act as no Emancipation Petition was filed.