Regarding David Maraniss’s Feb. 26 op-ed, “The man of the House”:

Master legislator John D. Dingell (D) has ably represented the 12th District of Michigan for more than 58 years, but his accomplishments reach far beyond his district. One of his lesser-known achievements occurred in 1959, when he authored and shepherded to enactment a bill that added the Dyke Marsh Wildlife Preserve in Fairfax County to the national parks system.

This 485-acre preserve along the shoreline of the Potomac River is a rare, freshwater, tidal wetland supporting more than 300 species of plants, 6,000 arthropods, 38 fish, 16 reptiles, 14 amphibians and 270 birds. It is the only site in the upper Potomac zone with a breeding population of marsh wrens and has state-threatened breeding populations of least bitterns. Dyke Marsh is rapidly disappearing, but thankfully, a restoration plan is near.

Mr. Dingell’s bill preserved Dyke Marsh “so that fish and wildlife development and their preservation as wetland wildlife habitat shall be paramount.” Lucky for us, he had the foresight and concern to work beyond the parochial boundaries of his Michigan district. Congress, the nation, the people and, yes, the critters owe him great thanks.

Glenda C. Booth, Alexandria

The writer is president of Friends of Dyke Marsh.

I was intrigued to learn in Ruth Marcus’s Feb. 26 op-ed column on retiring Rep. John D. Dingell [“Losing the art of legislating ”] that the meaning of the word “congress” is “a coming together.” An old riddle suggests a somewhat different definition, whether in the dictionary or not: If “pro” is the opposite of “con,” what is the opposite of “progress”?

Robert Engelman, Takoma Park