Special Correspondent: Letter from St. Louis, August 25, 1862

I came across this article, which dovetails nicely with previously posted US Provost Marshal records, and sets their context. Below the specific section about Margaret A. Johnston and Edward William Johnston (of Eureka and St. Louis at the time). 

LETTER FROM ST. LOUIS

Sacramento Daily Union, Vol. 23, No. 3577, 15 September 1862. 

[Link to digitized electronic copy here.]

{FROM OUR SPECIAL CORRESPONDENT}

Important Arrests. 

These discoveries [Confederate guerilla activities in the outskirts of St. Louis County] have led to the most searching investigations as to the accessories of the rebels in this city, and some interesting evidence implicating several parties has been obtained. 

In the course of the investigation it was deemed expedient by General [John] Schofield to order every house in the suburbs, whether its inmates were loyal or disloyal, to be searched for arms. 

This order led to the arrest, of a brother of the celebrated rebel Joe Johnston, of Virginia, and his wife, the rebel General's sister-in-law. The woman was arrested first for abusive and highly insulting language toward the Provost Guard, who visited her dwelling. 

After she had been arrested, Edward William Johnston, formerly editor of the Richmond Whig, and recently Librarian of the Mercantile Library, called at the Provost Marshal's office for a permit to visit his wife. He was informed that, all visits to military prisons were prohibited. 

Whereupon, Edward William, who is of an exceedingly excitable nervous temperament, became furious, and speedily subjected himself to arrest likewise. He had gone to keep his wife company. 

Johnston is fifty years of age [he was sixty-three at the time], of cultivated taste and extensive literary knowledge. He is an undoubted rebel at heart, but has had sufficient sense to keep quiet of late, and excepting for the unfortunate temper of his wife, would have avoided imprisonment as long as he lived in this city. 

Meanwhile, loyalty tests were being administered in Missouri. Here's an example from the same issue of the newspaper listed above, dated August 23, 1862.