Langholm on Wikipedia.
 

The former All Saints (Episcopal) as seen by Streetview in 2021. It's dated here to 1887, closing "sometime after 1995". NY 3616 8516.

The former Evangelical Union Church on Drove Road was seen by Streetview in 2021. Dating from 1870, it closed post-1960 (source). NY 3653 8457.

This source lists a large Victorian house called Erkinholme as a former Franciscan Convent, but provides no further details. Not seen by Streetview, a photo can be seen on a sale notice. NY 3646 8491. 

A map from 1899 shows a Mission Church on George Street, at NY 3626 8445. Pevsner calls it a Free Mission Hall, dating it to 1881. It was seen by Streetview in 2018, but by 2021 it had been demolished.

The former North United Presbyterian Church (2021 Streetview) stands on High Street. Latterly Erskine CoS, it's dated here to 1866-7, on the site of earlier churches, the earliest - Langholm Secession Burgher Church - of 1781-4. NY 3637 8468.

The former Relief Church on Drove Road, as seen by Streetview in 2021. This source dates it to 1805-7 and says it was subsequently South United Presbyterian Church (closing in 1928), and later St. Francis of Assisi R.C. Church (1976-2010). NY 3655 8447.

The Parish Church on Caroline Street is dated here to 1842-6, replacing an earlier church on Alma Place. NY 3615 8446. © Bill Henderson. Link. Category A listed. Not a great deal survives of the earlier 1702 church - photos of which can be seen on Wikipedia here. NY 3650 8463. Category C listed. Its medieval predecessor was Wauchope Church, to the S.W. of the town, at NY 3553 8411. Its graveyard survives (2021 Streetview). Category B listed.