Place: Mexico, Flag/origin

The Mexican flag.
The green in the flag represents 'The Independence movement'.  The white represents 'The purity of the Catholic faith'.  And the red represents 'The Spaniards that joined in the quest for independence' and 'The blood of the national heroes.'

The emblem-shield  symbolizes the Aztec heritage.
According to a beautiful legend, the gods had advised the Aztecs that the place where they should establish their city was to be identified when they saw an eagle, perched on a prickly pear tree, devouring a serpent.  They saw this mythical eagle on a marshy lake that is now the zócalo or main plaza in Mexico City.
This flag was created in 1821, when the Independence movement had ended victoriously.
El Día de la Bandera or the Fiesta of the Mexican Flag is celebrated on February 24.
Sourced: http://www.inside-mexico.com/flag.htm

- Need to find out more about 'The Independence movement'.

The Mexican War of Independence (1810–1821) was an armed conflict between the people of Mexico and the Spanish colonial authorities which started on 16 September 1810. The movement, which became known as the Mexican War of Independence, was led by Mexican-born Spaniards, Mestizos and Amerindians who sought independence from Spain. It started as an idealistic peasants' rebellion against their colonial masters, but ended as an unlikely alliance between Mexican ex-royalists and Mexican guerrilla insurgents.
Sums up briefly something I have little knowledge on.  Concise description.
Sourced: http://en.wikipedia.org/wiki/Mexican_War_of_Independence

- Look further into the 'War of Independence'.

Miguel Hidalgo y Costilla, was a Mexican priest and member of a group of educated Criollos in Querétaro who met in tertulias (salons) and who in 1810 arrived at the conclusion that a revolt against the colonial government was needed because of the events of the Peninsular War. Hidalgo had already achieved notoriety—he gambled, fornicated, had children out of wedlock and didn't believe in Hell. Most seriously, he encouraged his parishioners to illegally grow vines and olives. Originally Hidalgo worked closely with co-conspirator Ignacio de Allende, a noble and member of the Basque society living in San Miguel. Hidalgo originally supported naming Allende head of the revolutionary military, but the two men quickly became rivals. Hidalgo seized control of the militia. The conspirators were betrayed by a member of the group and Hidalgo turned to his parishioners in the town of Dolores. Around 6:00 am of September 16, 1810 he declared independence from the Spanish crown, and war against the government in what was known as the Grito de Dolores. The revolutionary army decided to strike for independence and marched on to Guanajuato, a major colonial mining centre governed by Spaniards and criollos. There the leading citizens barricaded themselves in the granary. The rebel army captured the granary on 28 September, and most of the Spaniards and Criollos were massacred or exiled. Among the many dead were nobles who were co-conspirators like Allende, who never forgave Hidalgo for the massacre. Consequently, Allende refused to fight alongside Hidalgo, and the two divided forces were easily defeated.

On October 30, Miguel Hidalgo's army encountered Spanish resistance at the Battle of Monte de las Cruces, fought them and achieved victory. However, the rebel army failed to defeat the large and heavily armed Spanish army in Mexico City. Rebel survivors of the battle sought refuge in nearby provinces and villages. The insurgent forces planned a defensive strategy at a bridge on the Calderón River, pursued by the Spanish army.

In January 1811, Spanish forces fought the Battle of the Bridge of Calderón and defeated the insurgent army, forcing the rebels to flee towards the United States-Mexican border, where they hoped to escape.^[2] However they were intercepted by the Spanish army. Hidalgo and his remaining soldiers were captured in the state of Coahuila at the Wells of Baján (Norias de Baján). They faced court trial of the Inquisition on 30 July 1811, and were executed. Hidalgo's body was mutilated, and his and Allende's heads were displayed in Guanajuato as a warning to Mexican rebels.
Following the death of Father Hidalgo, the leadership of the revolutionary army was assumed by José María Morelos. Under his leadership the cities of Oaxaca and Acapulco were occupied. In 1813, the Congress of Chilpancingo was convened and on 6 November of that year, the Congress signed the first official document of independence, known as the "Solemn Act of the Declaration of Independence of Northern America". It was followed by a long period of war at the Siege of Cuautla. In 1815, Morelos was captured by Spanish colonial authorities, tried and executed for treason in San Cristóbal Ecatepec on 22 December.

From 1815 to 1821, most of the fighting by those seeking independence from Spain was done by isolated guerrilla bands. Out of these bands rose two men, Guadalupe Victoria (born José Miguel Fernández y Félix) in Puebla and Vicente Guerrero in Oaxaca, both of whom were able to command allegiance and respect from their followers. The Spanish viceroy, however, felt the situation was under control and issued a general pardon to every rebel who would lay down his arms.

After ten years of civil war and the death of two of its founders, by early 1820 the independence movement was stalemated and close to collapse. The rebels faced stiff Spanish military resistance and the apathy of many of the most influential criollos. The violent excesses and populist zeal of Hidalgo's and Morelos's irregular armies had reinforced many criollos' fears of race and class warfare, ensuring their grudging acquiescence to conservative Spanish rule until a less bloody path to independence could be found. It was at this juncture that the machinations of a conservative military caudillo coinciding with a successful liberal rebellion in Spain, made possible a radical realignment of the proindependence forces.

In what was supposed to be the final government campaign against the insurgents, in December 1820, Viceroy Juan Ruiz de Apodaca sent a force led by a royalist criollo officer, Colonel Agustín de Iturbide, to defeat Guerrero's army in Oaxaca. Iturbide, a native of Valladolid, had gained renown for the zeal with which he persecuted Hidalgo's and Morelos's rebels during the early independence struggle. A favorite of the Mexican church hierarchy, Iturbide was the personification of conservative criollo values, devoutly religious, and committed to the defense of property rights and social privileges; he was also disgruntled at his lack of promotion and wealth.

Iturbide's assignment to the Oaxaca expedition coincided with a successful military coup in Spain against the monarchy of Ferdinand VII. The coup leaders, who had been assembled as an expeditionary force to suppress the American independence movements, compelled a reluctant Ferdinand to reinstate the liberal Spanish Constitution of 1822. When news of the liberal charter reached Mexico, Iturbide saw in it both a threat to the status quo and an opportunity for the criollos to gain control of Mexico. Ironically, independence was finally achieved when conservative forces in the colonies chose to rise up against a temporarily liberal regime in the mother country. After an initial clash with Guerrero's forces, Iturbide switched allegiances and invited the rebel leader to meet and discuss principles of a renewed independence struggle.

While stationed in the town of Iguala, Iturbide proclaimed three principles, or "guarantees," for Mexican independence from Spain; Mexico would be an independent monarchy governed by a transplanted King Ferdinand, another Bourbon prince, or some other conservative European prince, criollos and peninsulares would henceforth enjoy equal rights and privileges, and the Roman Catholic Church would retain its privileges and position as the official religion of the land. After convincing his troops to accept the principles, which were promulgated on February 24, 1821, as the Plan of Iguala, Iturbide persuaded Guerrero to join his forces in support of the new conservative manifestation of the independence movement. A new army, the Army of the Three Guarantees, was then placed under Iturbide's command to enforce the Plan of Iguala. The plan was so broadly based that it pleased both patriots and loyalists. The goal of independence and the protection of Roman Catholicism brought together all factions.

Iturbide's army was joined by rebel forces from all over Mexico. When the rebels' victory became certain, the viceroy resigned. On August 24, 1821, representatives of the Spanish crown and Iturbide signed the Treaty of Córdoba, which recognized Mexican independence under the terms of the Plan of Iguala. On September 27 the Army of the Three Guarantees entered Mexico City and the following day Iturbide proclaimed the independence of the Mexican Empire, as New Spain was to be henceforth called. The Treaty of Córdoba was not ratified by the Spanish Cortes. Iturbide, a former royalist who had become the paladin for Mexican independence, included a special clause in the treaty that left open the possibility for a criollo monarch to be appointed by a Mexican congress if no suitable member of the European royalty would accept the Mexican crown. Half of all the government employees were Iturbide's courtiers.

On the night of the May 18, 1822, a mass demonstration led by the Regiment of Celaya, which Iturbide had commanded during the war, marched through the streets and demanded that their commander-in-chief accept the throne. The following day, the congress declared Iturbide emperor of Mexico. On October 31 Iturbide dissolved Congress and replaced it with a sympathetic junta.

Sourced: http://en.wikipedia.org/wiki/Mexican_War_of_Independence

'The War of Independence' bulletpoints:

-  Began September 16th 1810, ended on September 27th 1821.
-  Took place in Viceroyalty of New Spain or Mexico

-  Was initiated because Mexico wanted to be independent from Spain

-  The Mexican side were the 'Patriots' which consisted of mexican insurgents; europeans and volunteers; mexican ex-royalists; army of the three guarantees.
-  The Spanish side were the 'Royalists' which consisted of spanish royalists; and mexican royalists.

-  The Patriots had 123,000 regular and irregular troops, whilst the Royalists had 17,000.
-  Only 1,000 died.
-  Resulted in the first Mexican Empire independent from Spain.

- Look further into Catholic faith within Mexico.

The Catholic Church is the world's largest Christian church, and its largest religious grouping. The 2000 census reported that Mexico had some 101,456,786 Catholics among the population aged five and above, which equates to around 91% of the total population, making it the second largest Roman Catholic country in the world after Brazil. The country is divided into 90 dioceses, and there are 15,700 priests and 46,000 men and women in religious orders.
Sourced: http://en.wikipedia.org/wiki/Roman_Catholicism_in_Mexico

-  Essentially Mexico is the second largest Roman Catholic country in the world after Brazil.
-  Bishop Andres Segura was sentenced to eight years in jail after his involvement within the Revolution, and the church was forced to pay 500,000 pesos in reparations for suffering victims.
-  After this, in the 1917 Constitution laws were made revolving around reducing the Catholic Church’s influence within Mexico, such as:  Article 19:

 

Article 3:

'I. According to the religious liberties established under article 24, educational services shall be secular and, therefore, free of any religious orientation. II. The educational services shall be based on scientific progress and shall fight against ignorance, ignorance's effects, servitudes, fanaticism and prejudice.'

Coat of arms The current coat of arms Main article: Coat of arms of Mexico According to the official story of Mexico, the coat of arms of Mexico was inspired by an Aztec legend regarding the founding of Tenochtitlan. The Aztecs, then a nomadic tribe, were wandering throughout Mexico in search of a divine sign that would indicate the precise spot upon which they were to build their capital. original eagle, from the Mendoza codex A closer look at the original Aztec codices, paintings, and the post-CortesianCodex Fejérváry-Mayer depicts an eagle attacking a snake, other Aztec illustrations, like the Codex Mendoza, show only an eagle, while in the text of the Ramírez Codex, Huitzilopochtli asked the Aztecs to look for an eagle devouring a precious bird perched on a prickly pear cactus. In the text by Chimalpahin Cuauhtlehuanitzin, the eagle is devouring something, but it is not mentioned what it is. Still other versions show the eagle clutching the Aztec symbol of war, the Atl-Tlachinolli glyph, or "burning water". codices shows that there was no snake in the original legends. While the The bird featured on the Mexican coat of arms is the Golden Eagle. This bird is known in Spanish as águila real (literally, "royal eagle"). In 1960, the Mexican ornithologist Martín del Campo identified the eagle in the pre-Hispanic codex as a Northern Caracara or "quebrantahuesos", a species common in Mexico (although the name "eagle" is taxonomically incorrect, as the caracara is a type of falcon). Even so, the Golden Eagle is considered the Mexican eagle for official purposes, and for the same reason is considered the official bird of Mexico. Sourced: http://en.wikipedia.org/wiki/National_symbols_of_Mexico