By Leon Kaye Few institutions in the nation’s capital are older than WGL Holdings. Its history dates back to 1848, the same year the Washington Monument’s construction began and 15 years before the U.S. Capitol’s iconic dome was completed. In fact, one of the company’s first projects (when it was known as Washington Gas) was to build a power plant that could reliably source and deliver gas necessary to light the Capitol’s dome. In addition, one of the chartered company’s most important missions was to ensure D.C.’s streets were safely lit at night. A decade after its founding, the company boasted 30 miles of gas mains, 500 street lights and 1,700 customers. No one talked about “sustainability” or “energy efficiency” during the mid-nineteenth century, though Washington Gas had already become adept at procuring natural gas and coal at a competitive price – necessary to accommodate the rapidly-growing city and crucial when the country lurched into the Civil War.