The world has changed a lot over the last 50 years, but what hasn't changed is what makes a business great -- and it's a good guess that it won't change any time soon.

The best companies last, and they last because they operate in a stable industry, are consistently profitable, and have a competitive advantage. I'd like to look at two companies that are not only built to last the next 50 years and beyond, but will pay a growing dividend in the process. 

Stable industry
In 1752, Benjamin Franklin founded the Philadelphia Contributionship for the Insurance of Houses from Loss by Fire, and believe it or not, it still exists today. The beauty of insurance is that it is human nature to want protection from the unknown, and it is why insurance will continue to stand the test of time. 

Although you cannot invest in Franklin's company, you can invest in two other longstanding and successful insurance companies, Chubb (NYSE: CB), which was founded in 1882, and ACE Ltd. (NYSE:CB) founded in 1985. 

As predominately property and casualty insurers, Chubb and ACE cover many of the same types of risks as back in Ben Franklin's day -- property damage, loss of shipping cargo, agriculture, and so on. 

However, we live in dynamic times with ever-changing risks, and insurance is also an adaptable industry. For instance, cyber security may not have been a major concern in the 1700s, but it is today, and is now one of a wide range of policies ACE and Chubb can underwrite. Fifty years from now the risks may be different, but the need for businesses and individuals to protect themselves will always be a necessity. 

Consistently profitable 
Today, ACE and Chubb have dividend yields of 2.3% and 2.0%, respectively. But, more importantly, Chubb has been paying -- and increasing -- that dividend every year since late 1980s. Similarly, save for a stumble in 2009, ACE has increased its dividend for the last 20 years. This kind of consistency is only possible because ACE and Chubb are among the very best at what they do.   

When insurers earn more in customer premiums than they pay out in claims, it is called an underwriting profit, and it is measured using the combined ratio. Although it may sound simple to do, very few companies are able to consistently make money underwriting insurance; Chubb and ACE are two of them.

Like golf, the lower a company's combined ratio the better. Over 100%, however, means that a company's losing money. As you can see in the chart above, Chubb and ACE have consistently outperformed their industry peers.  

In general, insurance companies make money by investing their float, or the pool of customer's money they hold, until it needs to be paid out in claims. Because ACE and Chubb consistently earn an underwriting profit, they are essentially getting paid to hold clients' money. This is an enormous advantage -- but it's not their only advantage.

Competitive advantage
Chubb is a $24 billion market cap company and ACE is valued at $37 billion, and their size, resources, and financial strength are significant advantages. 

For instance, an insurance policy isn't worth the paper it is written on unless you trust that the insurer can cover damages when they occur. ACE and Chubb have earned an A++ rating from A.M. Best, which is the highest rating for financial stability. For large companies, or really anyone for that matter, they simply cannot trust their liabilities to anyone but the most financially fit. 

Equally important, today's largest companies are global in scale and their risks are anything but usual. ACE and Chubb's ability to underwrite a wide range of risks, combined with their global footprint (Chubb operates in 26 countries and ACE in 53), helps make them the ideal insurers for large businesses around the world. 

Ultimately, by operating in an industry that will never go out of style, ACE and Chubb will be relevant for a long time. Moreover, each of them shows financial strength, consistent performance, global reach, a wide array of product offerings, and a track record built through decades of reliable service that would be difficult for competitors to replicate. Therefore they each have an advantage that I expect them to strengthen over time. This makes Chubb and ACE two of the top dividend stocks for the next 50 years.