Moss for boggy lawn?
There are many types of mosses that grow naturally in Maryland. In Howard County alone, there are quite a few species. https://www.howardbirds.org/flora-fauna/hocomosses.pdf
Mosses do not have roots and need consistent moisture to survive. Most species do best in moist shady areas. If you already see moss growing in or near this area, you can allow it to spread naturally over time as a groundcover or propagate it by spreading pieces that you already have. This publication from Virginia Cooperative Extension has information on how to grow moss. https://pubs.ext.vt.edu/content/dam/pubs_ext_vt_edu/430/430-536/430-536_pdf.pdf
If you find that this area tends to have standing water often, you might also want to explore the resources we have on stormwater management. See the following page and look in the section on "water resources" for further information and options. https://extension.umd.edu/hgic/topics/stormwater-management