Historic Congressional Cemetery at 1801 E Street SE has received Level I Arboretum Accreditation through ArbNet, which HillRag reported on October 18. The cemetery had announced it on its own blog on September 1.
The accreditation came alongside other changes at the cemetery. In 2026 the grounds also got fixed public hours and rewritten dog-walking rules. There's a new 2026 brochure for the numbered tree route with its QR-coded tags, and a calendar of ticketed programs runs through December. In its March announcement about the new hours, the cemetery calls itself "an active civic green space visited by thousands each year." Those rules and dates decide when and how you can use the grounds in November and December.
A Bylaw From 1811 and a Grant From 2024
The idea isn't new. According to HillRag, the cemetery's 1811 bylaws called for the grounds to be cared for and "ornamented" with trees. The recent work started in 2024 with a three-year Partners for Plants grant awarded by the Garden Club of America and the Trowel Garden Club, in partnership with Casey Trees.
ArbNet's Level I accreditation asks for more than tree diversity. The cemetery's announcement lists the standards it met: more than 25 tree species, a care plan, education resources and environmental programming. The announcement thanks Kennedy Simpson, Liam Ulsavech and Sharon Metcalf for the effort. Metcalf's title on the cemetery's team page is Circle of Life Designer & Arboretum Partnership Coordinator.
A care plan and an education program need something visitors can follow, and that turned out to be a walking route.
The Quarter Mile, Stop by Stop
The cemetery's "Tree Walk Through History" is a self-guided, quarter-mile path. Its database lists 27 numbered tree stops. Tagged trees carry QR codes. The cemetery also posts a downloadable walking-tour PDF and an online tree database on its trees page, so you can do the walk with just your phone.
Along the route, these are the stops with the most history behind them:
- The swamp white oak. The cemetery calls it a witness tree. It appears in photographs from 1913, and its database entry puts its age at more than 120 years. It's the oldest documented link between today's grounds and the cemetery's long-running instruction to plant trees.
- The tree tunnels. The walk passes through allées, rows of trees whose branches form a covered path. The cemetery names American hornbeam, Kwanzan cherry and Chinese elm among the trees that form them.
- The sugar maple and southern magnolia. Both are featured stops in the 2026 brochure, along with the cherries and elms.
- The Circle of Life. This is a contemplative gathering space ringed by a "tree-henge" of eight American lindens, also called basswoods, planted in 2020. Each tree lines up with a point on a central compass sundial. As the lindens grow, their shadows are meant to mark the seasons and the sun's path at the solstices and equinoxes.
The last three numbered stops on the database are a Japanese maple, a Yoshino cherry and an Okamé cherry. The route mixes a century-old oak with lindens planted six years ago, and that mix is what the accreditation recognizes: a planted collection that's maintained and still growing.
The Rules That Changed This Year
Unlike a Capitol Hill pocket park, the cemetery has a gate schedule. The change most likely to catch someone off guard is the hours. Starting March 23, 2026, the grounds are open to general visitors from 7 a.m. to 7 p.m. every day. That replaces the dawn-to-dusk wording still shown on an older rules page. If you're still inside after closing, an exit button at the gate lets you out. The rules page says to enter at the gate at 18th Street SE and E Street SE.
The dog-walking program, known as the K9 Corps, sits on top of those hours with its own rules:
| K9 Corps detail | 2026 terms |
|---|---|
| Volunteer membership | $400, plus eight household volunteer hours |
| Non-volunteer membership | $500 |
| Each additional dog | $50, up to two added dogs |
| Day pass for nonmembers | $15 per dog |
| Membership year | March 1 through the last day of February |
| New member enrollment | Lottery held each January |
| Weekly closure | Every Saturday, 11 a.m. to 3 p.m. |
| After-hours access | Gate code for members only, not day-pass holders |
The February 2026 K9 Corps rules also require dogs to be spayed or neutered and current on rabies and distemper shots, with current tags on member dogs. Members and day-pass holders may let dogs off leash where it's allowed. Dogs must be leashed coming in and going out, toys aren't allowed, and dogs may not climb on the grassy areas covering family vaults. Dog walking also stops during funerals, services and special events, so the cemetery tells walkers to check its alerts and the signs at the gate. Since enrollment happens by lottery in January, anyone hoping to join in 2027 should keep an eye on the K9 Corner page at the start of the year.
How the Calendar Runs Into the Dog Schedule
The Saturday closure and the event calendar are tied together. Half of the remaining program dates fall on Saturdays, and every one of those starts at 11 a.m., inside the 11 a.m. to 3 p.m. window when the grounds belong to visitors without dogs. These are the dates still ahead as of early November, from the cemetery's November and December calendars:
- Friday, November 6, 12:30 to 1:30 p.m. The John Philip Sousa birthday program is free. It includes a short ceremony and a lecture, followed by a performance from the Marine Corps Band. Dogs aren't allowed.
- Saturdays, November 7, 21 and 28 at 11 a.m., and Sunday, November 29 at 1 p.m. Docent-led introductory tours run about 90 minutes. Tickets are $5.
- Tuesday, November 10, 6:30 to 8 p.m. The Tombs and Tomes book club meets in person. Bring a $5 donation, or food or wine to share.
- Saturday, November 14, 11 a.m. to 12:30 p.m. The last Cemetery Speaker Series program of 2026 features Dr. Matthew Goetz on the White House residence staff, followed by a walking tour of the grounds. Tickets are $10.
- Thursday, December 3, 6 to 7:30 p.m. Death Cafe.
- Sunday, December 6, 11 a.m. to 4 p.m. The HCC Holiday Market is free, and leashed dogs are welcome.
- Saturday, December 19, 11 a.m. to 12:30 p.m. Wreaths Across America is free with an RSVP. Wreath placement starts after the ceremony, at about 11:30 a.m.
Eastern Market Main Street's events page lists Wreaths Across America at noon. The cemetery's own event page lists 11 a.m., so plan around the earlier time.
The Tree Walk is self-guided. With the PDF and the QR tags, you can walk the quarter mile on your own any day between 7 a.m. and 7 p.m. One easy pairing is to walk it right before a Saturday introductory tour, then join the docent at 11 a.m. for the people buried under those trees. The swamp white oak in the 1913 photographs has been there through most of that history.
The cemetery's fall 2026 wish list shows what's still underfunded. As of September 20, hoses, a datalogger and a foldable cart had reached their goals. Field-trip funding, laptops, a projector, a snowplow attachment and a wood chipper were still open. The cemetery also runs a tree sponsorship program for anyone who wants to put their name on the collection.
Maggie Daley has spent more than 30 years on Capitol Hill, and places like Congressional Cemetery are part of why the Hill East blocks feel the way they do. If you'd like to talk about life near the cemetery and the streets around 18th and E, schedule a consultation and Maggie will be glad to compare notes.
