The plant in your had is tall fescue. Tall fescue leaf blade is ridged on one side and smooth on the other and new leaves are rolled. You probably have kentucky bluegrass mixed in as well. The leaf blade is not as wide as tall fescue and smooth on both sides, also new leaves are folded.

Most turf grasses tend to be blends with a couple of distinct exceptions, usually associated with hot and rather dry climates. I would be very surprised if you lawn wasn't a blend of different turf grasses as well. And those blends are extremely hard to differentiate, especially with only a photo. I'd suggest taking a sample to your local extension service for an accurate ID. And after identification, they will be able to guide you with your care needs - unfortunately, info from Purdue (Indiana) is not going to be very relevant for the southern Atlantic coast :-)) You could also try posting in the Lawn Care forum or your regional forum. Not sure they'd be able to ID exactly for you but can certainly help with regionally appropriate care tips.

What a nice crop of beautiful photos! I like your seedling Bodacious Bite X Thin Man. I like the recurving it does. And red with yellow always slays me, so I like the Fire Agate X Thin Man seedling too. What is the size on Sergeant Major? It looks huge. The Carpenter seedling and Renegade Lady are both very appealing. You have posted an altogether nifty group. Thanks. kay

Terrific photos! How wonderful that you got 4 fledglings and it's nice to see pics of them. They look like they are enjoying the banquet!