I would guess that the barricades are NPS property. There are enough high-profile large events on the National Mall and elsewhere in DC that they likely get used fairly often.
That ain't how DC works. It runs on contracts and kickbacks. These barriers are rentals - rented from favored companies who are generous in their under the table kickbacks and in their overt political donations. I gar-on-tee!
But the signs were very specific to the occasion. They had to have been ordered and purchased literally months ahead of time, the procurement process being what its. Idea, authorization, design, specifications, numbers, invitation to bid, 30 days or more bid time, bid award, production, delivery and distribution all over the nation and Europe too. Don't kid me Barack. This was PLANNED LONG AGO and you and Jarrett et al. did it.