After Texas was annexed into the U.S. in 1845, very few Mexicans ventured north. Actually, the flow was south as Mexicans returned to their country. In the 1890s, a boom in mining and agriculture attracted Mexican immigrants back into the States. There was plenty of work available and American employers admired the Mexican work ethic. The Mexican Revolution (1910-1920) resulted in war refugees crossing into the U.S. Legal migration grew from 20,000 per year to almost 100,000 per year in the 1920s.

The Immigration Act of 1924 was crafted in part from American concerns about Asian and Southern European immigrants being "different" from previous generations of Western Europeans. Some felt they posed a threat, and some of this thinking was based on the misguided concept of eugenics. Mexicans were thought to have "better qualities" than other immigrants and so were exempted from the Act, primarily due to pressure from the powerful agricultural lobby.

The Great Depression in 1929 resulted in a decreased need for migrant labor. Many Mexican migrants became poor and moved back to Mexico. Thousands more were deported under unofficial repatriation policies that were never codified into law. The Mexican population in the U.S. fell by 40 percent during the 1930s. The sentiment that immigrants were taking jobs away from needy Americans also took root during this time. As World War II ended, the economy ramped up, especially in California. The preference was for migrants to work the fields and then return to Mexico after the harvest. Farmers were also against any type of cap on the number of Mexican immigrants. The Bracero Program of 1942 established the migrant as a "guest worker." That program ended in 1964. In 1952, the Texas Proviso was signed making it a crime to harbor illegal immigrants but exempted businesses from being liable in hiring them.

The immigration issue became more complicated in the 1960s. The "illegal alien problem" was a defining issue for Congress after the 1965 reforms posted in the Hart-Celler Act. This eliminated the quota system but established caps on the number of immigrants from all countries. Families received preference when filing for legal status. Congress recognized the issue as a hornet's nest and had little appetite for genuine reform due to liberal groups and businesses opposed to enforcing immigration laws while labor unions and social conservatives opposed new admissions of immigrants. Does this sound familiar?

Three consecutive presidencies convened task forces to study the "immigration problem." Spending on border patrols increased five-fold between 1970 and 1985. President Reagan signed the Immigration Reform and Control Act in 1986. This provided a path to legalization for those who entered prior to 1982 but excluded many spouses and children. It included two amnesty programs for unauthorized aliens, and granted amnesty to more than 3 million illegal aliens. Reagan exempted 200,000 Nicaraguan exiles from deportation in 1987. This Act was expanded in 1990 to increase the level of diversity in immigration from "underrepresented" countries. The Family Fairness Program was put in place by George H. W. Bush in 1990 by executive order and was similar to what President Obama attempted during his terms.

In 1996 the United States was in the midst of recession. This resulted, again, in anti-immigrant sentiment rising as well. So Congress passed the Immigration Reform and Immigrant Responsibility Act. This put limits on the use of social programs by immigrants and again increased border enforcement. In 2001, President Bush and Vincent Fox of Mexico had reached agreement on bilateral immigration reforms just days before September 11. The attacks on New York caused the agreement to be scrapped.

Obama's policies on immigration are not so much different than Trump's. He deported more illegal immigrants than any other president. But if separation of children from parents was occurring on Obama's watch, as some have alleged, why didn't conservatives and media object? Shame on them for not doing their job in bringing it to light.

You can draw your own conclusions on immigration based on your own reading of history. But what is obvious is that this is not an easy issue to fix. Campaign slogans don't often translate into workable solutions. Money, drugs, economics, and corrupt governments in Central America work to complicate the issue even more. But what we do need is compassion. The vast majority of those crossing illegally are not criminals, cartel members, or in the sex trade. They simply want to live in peace, free from fear. If the United States can't help those huddled masses at our border, perhaps we should change the words on the Statue of Liberty.

-- Devin Houston is the president/CEO of Houston Enzymes. Send comments or questions to [email protected]. The opinions expressed are those of the author.