Joshua Johnson was a self-taught portrait artist that spent most, if not all, of his life in the United States. There is limited reliable information on this artist, besides census information and a slave manumission in Baltimore County, Maryland. According to these documents, Johnson was born into slavery around 1763 to a white father, George Johnson, and an unnamed black slave who was owned by another. The slave manumission showed his father purchased him in the fall of 1764 and granted him his freedom upon the completion of his apprenticeship with a local blacksmith or when he turned 21, whichever came first. In 1782, Johnson gained his freedom and was listed as a portrait painter in the census while living in an area of Baltimore that contained a high percentage of painted chair fabricators. He may have supplemented his income as a furniture painter while he painted portraits. He married his first wife, Sarah, in 1785 and had three or four children.
In 1798, Johnson placed an ad for portrait paintings in two local papers claiming he was a “self-taught genius” who had "experienced many insuperable obstacles in the pursuit of his studies” which implied that he did not receive any formal training. He married again in 1803 and moved around a bit after 1825 to Frederick County and then to Anne Arundel County, Maryland a few years later. Before the mention of Joshua Johnson was lost in the records, it was understood that he produced around 83 known portraits though not a single one contained a date that they were painted and only one contained a signature. Unfortunately, the year of Johnson’s death is unknown as well as the location.