It's impossible to look at just 19th Century relations between Africa and Europe when cultural transactions go back to antiquity. Mediterranean culture would in the most literal sense not exist without Africa and empires such as Rome would not have existed, or the great city states would not have existed if not for trade with Africa. For much of human history African and Middle Eastern cities were wealthier, more heavily populated, greater centers of learning, and generally more cosmopolitan than their European equivalents.

Ship building technology arising out of the Mediterranean trade and allowed Europeans after the reconquest of Spain from African and Middle Eastern powers and their great intellectual and cultural tradition which allowed the comparatively new Spanish and Portuguese kingdoms the ability to plunder the new world.

This newfound wealth allowed the Spanish and Portuguese to kick start the Atlantic Slave trade, with European powers slowly building, taking over, or destroying the atlantic port cities of Africa and the eventual exportation of millions of Africans to the Americas in order to provide material wealth extraction from the Americas back to Europe. Consequently it is hard to separate African Political Economy from European Political Economy from the 16th Century onwards, Since you have the great Arab traders to the East and the Western europeans to the West.

But we still see the development of rich African Empires and Kingdoms during this time which covered vast areas of land and introduced long periods of political and economic stability, with vast trading networks and cultural development, well into the 19th Century. But by this point the Europeans had amassed so much wealth and technology they were able to not so much take over Africa as finally fully poison the well of African political and cultural independence and they militarily and economically toppled all of the major societies in Africa in what are a series of stunning genocides that had require theories of whiteness and race to develop over the previous hundreds of years in order to stomache many of the greatest atrocities of all time.

While it is easy to just say that every human being is responsible for their own agency, many of the reasons that Africans are fighting themselves today were introduced by Europeans.

Take for example the Hutus and the Tutsis, who until the Germans and Belgians had lived generally peacefully but then were told that they were separate peoples with the Tutsis were the descendants of the Biblical Hamm. It is impossible to separate the destruction of the princely states and the introduction of the race myth into Rwanda and Burundi from any of the political unrest and genocides that have happened since. The primary reason that westerners are familiar with rwanda is not because of the genocide, but because large western corporations want to continue mining and large scale infrastructure programs in the region. To put it bluntly I could not in good conscience say that the Europeans were a net positive for the region based off the stunning tragedies of the 19th Century.

While there is a lot of interesting economic and technological developments that came out of Europe in the past few hundred years, it was ALL done in conjunction with the other world populations and in ways that we have largely dismissed because of the necessity of racist beliefs in order to be OK with our history.

While any child can tell you that railroads are cool, it is hard to emotionally and intellectually wrap ones head around the stunning amount of misery and unrest that was introduced into a continent in order to do technological modernization, at a tremendous cost to the lives, the politics, and the cultures of an entire continent.

TL/DR NO, They did not.

edit: I wrote this quickly on a lunch break. If you need sources I can offer up specific books this evening but most modern histories will do the job better than I can do while eating a sandwich.

In my work, I've also encountered (a minority) of Africans who speak of the benefits of European colonization. I listen respectfully, but usually I don't disagree. I see a couple of reasons for their views. First, this is a troubled time in many parts of Africa (although also one with great hope as middle classes emerge etc), and some people have nostalgia for a past that they perceive to have been better, when the "British made the trains run on time" etc. However, nostalgia is well known to be very misleading and selective, and that's part of what's going on here.

Second, colonization was a mental as well as a physical process. Colonial rulers purposefully implanted the idea of European superiority in every way, and these ideas have taken a long time to fade and sometimes crop up in interesting ways.

Personally, I must admit that even when I try to be objective I find the question problematic.