The front page of The Daily Union on June 3, 1846, is dominated by eyewitness accounts of General Zachary Taylor's stunning military victories in Mexico. A detailed letter from a soldier at the Battle of Resaca de la Palma describes how American forces, having just returned from Point Isabel with supply wagons, encountered Mexican forces near a prairie water hole called Palo Alto on May 8th. The engagement was fierce: Mexican cavalry of 1,000 lancers attempted to flank the American right and seize the wagon train, but the Fifth Infantry, formed in defensive squares, repelled them with devastating musket fire. Artillery under Lieutenants Churchill and Ridgely created "great confusion in their ranks, killing and wounding a great number of men and horses." The following day brought a second victory when American dragoons, led by Captain May, charged Mexican gun positions, driving the gunners from their cannons. The Americans captured eight artillery pieces, General Vega himself, 500-600 mules, and 400 stand of arms. The letter estimates Mexican casualties at 2,000 killed, wounded, and missing, with American losses described as "comparatively but trifling"—a claim that would prove optimistic in later reporting. Also featured is correspondence from a U.S. Navy officer aboard the USS Jamestown off the African coast, documenting the squadron's anti-slavery patrols and the toll tropical disease took on officers and crews.

June 1846 marked a pivotal moment in the Mexican-American War, which had begun just weeks earlier in April. Taylor's victories at Palo Alto and Resaca de la Palma would make him a national hero and propel him toward the presidency—he would win the 1848 election on the strength of these Mexican War laurels. This conflict was deeply connected to America's expansionist ideology: the war would ultimately add nearly 525,000 square miles to U.S. territory, including present-day California, Nevada, Utah, Arizona, New Mexico, and parts of Colorado and Wyoming. Yet even in 1846, these victories were stoking fierce debate back home about whether conquered territories would permit slavery—a question that would haunt the nation for the next fifteen years and help trigger the Civil War.

• The paper lists subscription rates in granular detail: 'six copies' to one address cost $5 per year, but 'ten copies' cost only $7—a bargain for bulk subscribers, suggesting newspapers were being shared within households and offices.
• An auction notice lists a 'six-barrel revolving pistol' among the estate items of Fountain A. Merrett—this is almost certainly a Colt revolver, the cutting-edge firearm technology of the era, suggesting the deceased was a man of considerable means and modern tastes.
• The Globe Hotel at Pennsylvania Avenue and 13th Street is being auctioned with the note it 'directly in front of the National Theatre and Union office'—this property would remain a fixture of Washington's commercial core for decades, yet is barely remembered today.
• One auction lists a 'rosewood piano forte, seven octaves, of fine tone and touch' as part of a household sale—pianos were luxury items costing $300-500, making this household one of the city's upper classes.
• A naval officer complains of receiving no news from Washington since 'last November' despite being stationed off Africa just five months prior—mail transit times meant military commanders operating on distant stations were essentially cut off from real-time information about their own government's actions.

• The letter writer mentions Major Ringgold was 'mortally' wounded at Palo Alto—Samuel Ringgold would die of his wounds eleven days later and become one of the first American officers killed in the Mexican-American War, celebrated as a martyr in the Northern press.
• General Vega, captured in the second battle, was a prominent Mexican general—his capture was a propaganda victory that Washington papers trumpeted. He would eventually be exchanged and return to Mexico, where he'd play a significant role in Mexican politics for decades.
• The African squadron was hunting slave ships under the antislavery flag when this letter was written—yet American naval power would be used just 15 years later to suppress the Union and defend slavery, as the Confederacy would seize many of these same vessels.
• Captain May's dragoon charge at Resaca de la Palma was celebrated as the battle's turning point—but the real tactical genius was artillery lieutenant Ridgely, who would go on to become one of the war's most innovative commanders and later a general in the Civil War.
• The 'five captures' mentioned by the navy officer refers to slave ships—by 1846, the U.S. Navy had become surprisingly effective at interdicting the slave trade while Americans at home debated whether slavery would expand into Mexican territories. The contradiction was not lost on contemporaries.