The province is rich in natural and cultural attractions, offering activities such as red clay pottery, grape picking, loom weaving, and pilgrimage tours to historic churches, alongside beautiful waterfalls and eco-tours.

During its early history, the province was inhabited by various ethnolinguistic groups, including the Ilocanos, Pangasinenses, and Cordillerans (Igorots), who actively engaged in trading and bartering while practicing animistic and polytheistic indigenous religions and traditions.

[8] This route facilitated the transport of gold from the Ibaloi villages of Acupan and Balatok in the southern areas of present-day Benguet to the trading centers of Aringay, with further distribution to the port settlement of Agoo.

[5] A year after Miguel Lopez de Legazpi made Manila the capital of the Philippines on June 24, 1571, the Spaniards started the colonization in Northern Luzon "to pacify the people in it".

[3] Salcedo then proceeded to Atuley (modern-day San Juan) and further north until they encountered a large Ilocano settlement called "Purao," referring to the gleaming white sands of its beaches along the South China Sea.

Captain Garcia de Aldana led expeditions into areas like Aringay, Bauang, and San Juan, while Sargento Mayor y Capitan Alonso Martin Quirante centralized the industry in 1624, deploying a force of 1,748 troops, including Spaniards, Chinese, Japanese, Mexicans, and 500 Ilocanos.

The commandancia established in 1826 proved ineffective in maintaining order among the Igorrotes, whose remoteness from central authorities led to rampant smuggling of tobacco and other merchandise, thereby disrupting the region's economic stability.

On September 10, 1896, Spanish authorities, led by Friar Rafael Redondo, arrested Dr. Lucino Almeida, the highest-ranking native official in La Union, along with other suspected revolutionaries.

[3]From May to August 1898, citizens of La Union fought several heroic battles against the Spanish forces in key towns such as Darigayos (Luna), Bacnotan, Rabon (Rosario), San Fernando, Bangar, and Balaoan.

Tinio's forces numbered 1,904, including 68 officers, 200 bolo men "hermano", 284 auxiliaries such as armorers, telegraphers, medical corpsmen, cavalry, artillerymen, and two Spanish engineers stationed in Northern Luzon.

[3] On November 18, 1899, American forces under General Samuel Baldwin Marks Young entered La Union, landing in Rosario via Rabon Point along the coast in pursuit of Aguinaldo.

[19] Throughout the week, heavy fighting ensued between American forces and five Filipino guerrilla units in La Union led by Colonel Juan M. Gutierrez:[31] Simultaneous battles were fought across various towns, including Santo Tomas, Aringay, Naguilian, Bauang, and San Fernando.

[29] On November 20, General Young entered San Fernando where describe the town as “series of the most formidable entrenchments,” capturing the revolutionary headquarters and estimating the presence of 1,000 Filipino insurgents.

On the same day, La Union's insurrecto governor, Dr. Don Lucino Almeida y Almendrada, paid a courtesy call to General Young, offering assistance to the U.S. government.

Aniceto Angeles, Francisco Peralta, and Col. Juan M. Gutierrez were executed through public hanging and firing squad in Bangar and San Fernando town plaza, underscoring the conflict’s harsh aftermath.

[3] Despite this shift, U.S. military leaders, including Colonel Duvall, resisted relinquishing power and frequently clashed with the Philippine Commission, led by Civil Governor William Howard Taft.

Schools were established in key towns like San Fernando, Bangar, Rosario, Aringay, Cava, Agoo, Balaoan and Namacpacan (Luna), with some operating in repurposed Spanish-era convents.

[36] Battle of Rosario (Invasion of Lingayen Gulf) On December 22, 1941, the Japanese 4th Tank Regiment and the 47th Infantry Regiment under the command of Col. Isamu Yanagi, supported by a massive flotilla of navy ships tried to land in Agoo to make it one of three major beachheads for the Japanese Invasion of Lingayen Gulf, although weather dispersed their forces and made them deploy on a wide stretch of beach that ranged from Poro Point (San Fernando) to as far south as Damortis.

The operation began with an assault by the 121st Infantry Regiment of the United States Armed Forces in the Philippines, Northern Luzon (USAFIP-NL), against Japanese positions along the south bank of the Baroro River.

This victory played a crucial role in ensuring the liberation of La Union and was followed by subsequent operations, including the Battle of San Fernando and the capture of Bacsil Ridge.

The Japanese defenders called the Hayashi Detachment, composed of 3,000 armed troops and 2,000 unarmed support forces, took hold of San Fernando and its surrounding areas which denied entry to the port of the town and a road leading to Baguio.

[49][50] The following year, La Union Congressman Manuel T. Cases filed a bill to "limit the importation of foreign leaf tobacco," which was eventually signed by President Elpidio Quirino as Republic Act 698.

Many buildings, including the Agoo Municipal hall,[65] the Museo de Iloko, the parish church of Aringay,[66] and the Basilica Minore of our Lady of Charity,[67] collapsed or were severely damaged.

[68] They were initially attracted to the already-established surfing scene of Barangay Urbiztondo in San Juan, but eventually envisioned business in the province as an alternative to the stresses of city-based employment.

[79] La Union is home to nine valleys—four in the northern part of the province (Bangar, Balaoan, Bacnotan, San Juan) and five in the south (Tubao, Aringay, Santo Tomas, Rosario, Naguilian)—which support agricultural land.

Indigenous communities, including the Kankanaey (42,552), Bago (24,757), and Ibaloi (9,107), reside in the municipalities of Sudipen, Santol, San Gabriel, Bacnotan, Tubao, Pugo, Bagulin, and Burgos.

[123] Handicrafts also contribute to the local economy, with red clay pottery (damili) in San Juan, woodcarving and furnishing products in Pugo and Rosario, and rattan and bamboo basketry (laga) in Santol and Sudipen.

[128] The service sector is a vital driver of La Union’s economy, significantly contributing to the province’s development through trade, healthcare, education, commerce, transportation, and hospitality.

[129] The airport, covering 40.5 hectares, provides critical access to regional destinations, boosting tourism and trade, which contribute to local revenue and job creation.

Sillag means "moonbeam" or "illumination" in Iloco, and the festival features various light displays and activities that start at sunset, showcasing the beauty of Poro Point.